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Xamarin.Forms.2.3.4.247 update : project won't build RRS feed

  • Question

  • User323193 posted

    Hi,

    I just updated Xamarin.Forms to version 2.3.4.247 as well as a couple of other packages, and I get this error, completely new for me:

    ...\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets(68,4): error MSB4064: The "DebugType" parameter is not supported by the "XamlCTask" task. Verify the parameter exists on the task, and it is a settable public instance property. ...\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets(62,3): error MSB4063: The "XamlCTask" task could not be initialized with its input parameters.

    Any idea of possible cause of this error?

    The project was initially working with Xamarin.Forms 2.3.1.114, it is a PCL project, not using XMAL.

    Thank you.

    Wednesday, May 17, 2017 8:09 PM

All replies

  • User239957 posted

    I have the same problem too... can anyone help us?

    Thursday, May 18, 2017 1:36 AM
  • User12542 posted

    Same problem here. My project do not have any XAML

    Thursday, May 18, 2017 1:43 AM
  • User318136 posted

    I was unable to run my app with the previous version of Xamarin.Forms, so I updated, and this error is showing up for me too.

    Thursday, May 18, 2017 1:57 AM
  • User318136 posted

    Solved for me: Restarted my Visual Studio and rebuilt.

    Thursday, May 18, 2017 2:04 AM
  • User318657 posted

    Restarting and rebuilding hasn't worked for me. I'm seeing this error on both PC and Mac versions of Visual Studio, running on code that I know compiled and ran without issue yesterday. I even tried deleting the entire project, pulling a fresh version of the master branch, uninstalled and reinstalled Visual Studio - still getting that error.

    What did allow me to get past it temporarily was editing the Xamarin.Forms.targets file, which for me lived in: packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20 and removed the DebugType = "$(DebugType)" line.

    This obviously isn't a proper fix, though.

    Thursday, May 18, 2017 2:13 AM
  • User248173 posted

    @akadam

    below steps work for me

    step1:

    you have to maintain same xamarin.forms version in pcl, android and ios.

    step2:

    delete the bin and obj files in pcl, android and ios. then rebuild the solution

    Thursday, May 18, 2017 4:50 AM
  • User314437 posted

    Same problem here. some one get a solution for this problem?

    first help: downgrade Xamarin.Forms to 2.3.4.231 and it work again

    Thursday, May 18, 2017 9:15 AM
  • User323977 posted

    I'm also having the same problem. Please can anyone help me out ?

    Thursday, May 18, 2017 11:56 AM
  • User323193 posted

    Thank you all for you comments.

    @"Vaka.GopiNadhReddy" @JakeAnstey

    Checked that all the project reference Xamarin.Forms V 2.3.4.247

    Deleted every bin and obj folders in every project.

    Restarted Visual studio then try to rebuild

    => still getting the same error during PCL project compilation

    I'll try now to downgrade Xamarin.Forms to previous versions and try again.

    Thursday, May 18, 2017 12:16 PM
  • User46850 posted

    Hello. Closing visual studio and deleting ALL "bin" and "obj" folders has solved the problem for me. I'm using a Shared Project.

    Best regard, Marco

    Thursday, May 18, 2017 12:27 PM
  • User268424 posted

    I have PCL and try: - Downgrade to 2.3.4.231 version - Delete bin/obj folders inside

    Nothing work for me, another action to do?

    Thursday, May 18, 2017 1:03 PM
  • User17562 posted

    Same here

    It's only the release build for me that won't build. Debug builds fine, and runs on the emulator at least - not tested on a device yet

    VS 2017 Enterprise

    Thursday, May 18, 2017 1:06 PM
  • User67129 posted

    @ChrisRzepa said: Restarting and rebuilding hasn't worked for me. I'm seeing this error on both PC and Mac versions of Visual Studio, running on code that I know compiled and ran without issue yesterday. I even tried deleting the entire project, pulling a fresh version of the master branch, uninstalled and reinstalled Visual Studio - still getting that error.

    What did allow me to get past it temporarily was editing the Xamarin.Forms.targets file, which for me lived in: packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20 and removed the DebugType = "$(DebugType)" line.

    This obviously isn't a proper fix, though.

    This is probably the only solution that will work.

    My guess is that someone has compiled this package in a development environment and forgot to take their dev code out of the .targets file when publishing to nuget. This will probably only affect people who use XAMLC

    my advise is to follow the steps outlined above and wait for an updated nuget to be released, which would replace the .targets file anyway, so no permanent damage

    Thursday, May 18, 2017 1:32 PM
  • User323193 posted

    @ChrisRzepa that fixed the issue for me, thank you :)

    @JKay I didn't want to modify the .targets file but I understand now that it is safe to do so, thank you for the explaination !!

    Thursday, May 18, 2017 1:39 PM
  • User128353 posted

    Looks like they've patched it (hoping it's the same thing). Just have to wait for it to be released: https://github.com/xamarin/Xamarin.Forms/commit/f01cf880403f649cf6d6ccc71d930eae646bc698

    Thursday, May 18, 2017 7:57 PM
  • User256693 posted

    @MarcoRinaldi said: Hello. Closing visual studio and deleting ALL "bin" and "obj" folders has solved the problem for me. I'm using a Shared Project.

    Best regard, Marco

    This did it for me. The issue was happening while developing in Android. However I did a quick build to iOS then came back to Android. It got resolved only after deleting "bin" and "obj" from both iOS and Android

    Friday, May 19, 2017 3:12 PM
  • User112171 posted

    @Vaka.GopiNadhReddy said: @akadam

    below steps work for me

    step1:

    you have to maintain same xamarin.forms version in pcl, android and ios.

    step2:

    delete the bin and obj files in pcl, android and ios. then rebuild the solution

    Worked for me.

    Friday, May 19, 2017 6:57 PM
  • User140005 posted

    Closing visual studio and deleting ALL "bin" and "obj" folders has solved the problem for me as well. Make sure you close all instances of VS. I have a habit of having 2-3 instances up at the same time!

    Now if only I could get past the "The file "obj\Debug\android\bin\packaged_resources" does not exist." issue!

    Saturday, May 20, 2017 3:24 PM
  • User37558 posted

    I did a full git clean (i.e. delete all NuGet packages, bin, and obj folders) and the problem doesn't go away. I'm getting two errors and it has halted work.

    Severity Code Description Project File Line Suppression State Error The "XamlCTask" task could not be initialized with its input parameters. Adapt.Presentation.Helpdesk.Android C:\AdaptSource\Xivic\packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets 62
    Error The "DebugType" parameter is not supported by the "XamlCTask" task. Verify the parameter exists on the task, and it is a settable public instance property. Adapt.Presentation.Helpdesk.Android C:\AdaptSource\Xivic\packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets 68

    Monday, May 22, 2017 4:55 AM
  • User37558 posted

    All the dependency spaghetti in Xamarin Forms means that it's absolute pot luck as to whether a given project will compile for a given platform on any given day.

    Monday, May 22, 2017 4:57 AM
  • User37558 posted

    I wiped everything again, and did a Consolidate inside NuGet for the solution to make sure all my platforms have the same versions of Xamarin Forms etc. and I'm still getting this problem. Thanks Xamarin. Yet again, I find myself bashing my head against the wall just trying to get this stuff to compile.

    Monday, May 22, 2017 6:58 AM
  • User440 posted

    After trying all the workarounds suggested in this thread, I believe that this is the one that works.

    @JKay said:

    @ChrisRzepa said: Restarting and rebuilding hasn't worked for me. I'm seeing this error on both PC and Mac versions of Visual Studio, running on code that I know compiled and ran without issue yesterday. I even tried deleting the entire project, pulling a fresh version of the master branch, uninstalled and reinstalled Visual Studio - still getting that error.

    What did allow me to get past it temporarily was editing the Xamarin.Forms.targets file, which for me lived in: packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20 and removed the DebugType = "$(DebugType)" line.

    This obviously isn't a proper fix, though.

    This is probably the only solution that will work.

    My guess is that someone has compiled this package in a development environment and forgot to take their dev code out of the .targets file when publishing to nuget. This will probably only affect people who use XAMLC

    my advise is to follow the steps outlined above and wait for an updated nuget to be released, which would replace the .targets file anyway, so no permanent damage

    Monday, May 22, 2017 4:52 PM
  • User53097 posted

    This worked.

    What did allow me to get past it temporarily was editing the Xamarin.Forms.targets file, which for me lived in: packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20 and removed the DebugType = "$(DebugType)" line.

    Monday, May 22, 2017 7:10 PM
  • User67129 posted

    There has been a fix checked into github for this issue:

    https://github.com/xamarin/Xamarin.Forms/commit/f01cf880403f649cf6d6ccc71d930eae646bc698

    but is yet to be packaged for nuget. Probably in next build

    Tuesday, May 23, 2017 7:38 AM
  • User305535 posted

    First Step : delete all bin/ obj folders
    Second : Restart VS

    if problem not solved

    open packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets

    file remove blow lines

    DebugType = "$(DebugType)"

    Image Attached as below

    Tuesday, May 23, 2017 2:20 PM
  • User122681 posted

    Well, removing the DebugType entry works for release iOS build, but not for debugging in simulator. "XamlCTask" task failed unexpectedly. I also deleted all bin and obj directories as well.

    I gotta say... this xamarin thing has cost me probably close to $200k in lost production time over the last three years, not counting the costs of very expensive licensing up until recently. One thing after another, you just can't win with these guys. They're sloppy, and oftentimes unhelpful. Personally, I hope MS fires them all over time, and replaces them with competent people who actually know how to put together a PROFESSIONAL development environment.

    Saturday, May 27, 2017 7:32 PM
  • User122681 posted

    I went back over to using crappy xamarin studio. While it has a whole host of other annoying issues, I can at least compile and (for the most part) debug.

    Saturday, May 27, 2017 7:35 PM
  • User189 posted

    Frustrating issue. Obliterating output paths didn't do the trick, but closing VS (macOS) and then deleting all bin/obj directories (I did a directory search of my entire source repo, so unsure if it found something other people were not when manually deleting) and then re-opened and archived for publishing (is all I needed to do) and it worked.

    Wednesday, May 31, 2017 10:30 PM
  • User57571 posted

    @"Vaka.GopiNadhReddy" Solution of keeping the same versions for Xamarin.Forms along all projects worked for me too.

    Friday, June 2, 2017 5:11 PM
  • User72380 posted

    @RahulTripathi.1744 said: First Step : delete all bin/ obj folders
    Second : Restart VS

    if problem not solved

    open packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets

    file remove blow lines

    DebugType = "$(DebugType)"

    Image Attached as below

    works for me

    Friday, June 2, 2017 7:50 PM
  • User177542 posted

    I had to make sure that both iOS and Android apps in my project had the same version of Xamarin Forms to fix this.

    Saturday, June 3, 2017 5:25 AM
  • User279438 posted

    I just renammed an Image in Resource folder in Android Project and i got this error. WTF!

    But Restarting VS did the work for me.

    Monday, June 5, 2017 6:57 AM
  • User305646 posted

    I rollback Xamarin.Forms to version 2.3.4.231, then the error is gone.

    Waste too much time on it.

    Wednesday, June 7, 2017 12:34 PM
  • User329426 posted

    Sometimes it helps me to change Solution Platform from Any CPU to x64 or x86, recompile project, and then back to Any CPU.

    Thursday, June 8, 2017 7:09 PM
  • User4715 posted

    exit VS, delete all obj and bin folders, run VS and build. That fixed it for me.

    Friday, June 9, 2017 5:04 PM
  • User8762 posted

    Deleting my repo and re-cloning did the trick for me.

    Saturday, June 10, 2017 11:45 AM
  • User328125 posted

    @ChrisRzepa said: Restarting and rebuilding hasn't worked for me. I'm seeing this error on both PC and Mac versions of Visual Studio, running on code that I know compiled and ran without issue yesterday. I even tried deleting the entire project, pulling a fresh version of the master branch, uninstalled and reinstalled Visual Studio - still getting that error.

    What did allow me to get past it temporarily was editing the Xamarin.Forms.targets file, which for me lived in: packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20 and removed the DebugType = "$(DebugType)" line.

    This obviously isn't a proper fix, though.

    this worked thanks , what i did was Deleted the obj and the bin folder and then removed the line above clean - > build everything worked fine and then re added the line above :)

    Saturday, June 10, 2017 5:46 PM
  • User272328 posted

    In my case: 1. Uninstall Xamarin.Forms 2. Restart VS 3. Install Xamarin.Forms. 4. Build and Work

    Sunday, June 11, 2017 11:57 AM
  • User330278 posted

    I had the same issue too, In my case I have had updated only the App.Android assembly, forgetting the PCL's one.. my bad

    Tuesday, June 13, 2017 10:29 AM
  • User262652 posted

    Updating Visual Studio (for Mac) to latest build ( Version 7.0.1 (build 24)) solved the issue for me. I hope it helps.

    Thursday, June 15, 2017 2:08 PM
  • User183394 posted

    @MarcoRinaldi said: Hello. Closing visual studio and deleting ALL "bin" and "obj" folders has solved the problem for me. I'm using a Shared Project.

    Best regard, Marco

    +1. Thank you, Marco.

    Thursday, June 15, 2017 4:29 PM
  • User1004 posted

    Hey guys,

    Short Answer: - make sure EVERYTHING is up to date, clean, restart your IDE

    Long Answer, and the reasons why it fails:

    This error can have multiple causes (and some can be combined): 1. Some of the projects of your solution aren't updated to the latest version of XF. The problem is then that multiple versions of the Tasks assembly exists, but obviously a single one is loaded by msbuild in the AppDomain, and if it's not the latest one, it fails with the latest .targets file. If you think all of your projects are up-to-date, you can either grep your code to check for references in .csproj, but what I usually do is remove the packages folder, let nuget restore everything, and if I have more than one XF nuget package installed in packages/, that means there's still a reference. 2. restart your IDE. if you update XF, and if the update contains changes in the Tasks assembly, and if that assembly is loaded in the msbuild AppDomain. Reloading your solution should work, but restart your IDE to be sure. 3. cleaning all the bin/ and obj/ is always a good idea too. I do git clean -xfd.

    If it still fails Open an issue on bugzilla with your project, or a valid reproduction, and let me know. I'll look at it. If you have concerns about sharing your code, you can make the bug or the attachment private, and/or discuss NDA with @DavidOrtinau or any Xamarin Customer Support Engineer

    Friday, June 16, 2017 7:51 AM
  • User179852 posted

    I had the same issue so i did the following to resolve 1. Build > Clean All 2. Right click on each project from the solution panel, select Tools then Edit File. This will open the csproj file as text 3. Find all lines with Xamarin and ensure that it use version 2.3.4.247. 4. File > Close Solution 5. File > Close (make sure that Visual Studio is completely shutdown) 6. Open Finder and remove all bin and obj folder from each of your project 7. Open your solution and rebuild

    Friday, June 16, 2017 10:12 AM
  • User231046 posted

    The most important bit for me was in Stephane's instructions was:

    "...if I have more than one XF nuget package installed in packages/, that means there's still a reference."

    1. Update all Xamarin Forms packages to latest (stable latest in my case).
    2. With the solution open, Clean it.
    3. Close the solution and close Visual Studio.
    4. Delete all bin and obj folders in your solution. (If you're on a Mac, you can use this Automator script to add a "Remove bin and obj folders" context action in the OS X Finder: http://www.joesauve.com/remove-obj-and-bin-folders-via-os-x-finder/)
    5. Delete your packages/ folder.
    6. Re-open Visual Studio and your solution.
    7. Allow the packages to be restored (automatic on solution-open in VS for Mac)
    8. Observe your packages/ folder. If you see Xamarin.Forms.* folders with more than one version number, then you still have references in your solution (SOMEWHERE) to an older version of Forms.
    9. Use the "Find in Files" feature of VS to search the entire solution folder for the erroneous version number. (In my case it was "2.3.3.152"). You'll probably find instances of that in files like project.json and packages.config.
    10. Delete all references to those erroneous versions of Forms. (You may need some familiarity with packages.config and project.json to this without messing anything up, but it's not too hard.
    11. For safe measure, again Clean the solution, close it, delete bin and obj folders, and delete packages/ folder.
    12. Open the solution again and allow the IDE to restore packages. You should be able to build now.

    I was seeing the dreaded The "DebugType" parameter is not supported by the "XamlCTask" task. But now all is well.

    Monday, June 19, 2017 3:22 AM
  • User222315 posted

    @LRLin56 said: I rollback Xamarin.Forms to version 2.3.4.231, then the error is gone.

    Waste too much time on it.

    this is what i did, i guess i'll stay with 2.3.4.231 for a while

    Tuesday, June 20, 2017 5:54 AM
  • User68434 posted

    I had the same problem, I fixed it by following these steps... 1. Verifying that all of my projects had the same version of Xamarin.Forms. (It turned out that I had updated it in my PCL but not in my iOS project). 2. Close Visual Studio 3. Delete the bin and obj folders for your PCL, iOS, and Android projects 4. Also Delete your packages folder (to get rid of the multiple copies of Xamarin.Forms) 5. Reopen Visual Studio and Build

    Wednesday, June 21, 2017 1:25 AM
  • User322335 posted

    @YuriShteinman said: exit VS, delete all obj and bin folders, run VS and build. That fixed it for me.

    I did the same thing to my Android project and it worked.

    Thursday, June 22, 2017 1:52 AM
  • User258859 posted

    Deleting the bin/obj folders and restarting vs works, not editing the target files for me. However this bug quickly returns and restarting VS every time is not an ideal solution.

    Monday, June 26, 2017 9:20 PM
  • User25759 posted

    So, this one actually has to do more with NuGet and perhaps not removing and updating the csproj file correctly.

    For instance I updated to 2.3.4.247 from an older version and NuGet didn't know how to upgrade and left old busted imports around. Sooo, unload your projects and look into the bottom of all the csproj files for things that aren't correct.

    For instance I had these two lines: <Import Project="..\packages\Xamarin.Forms.2.0.1.6492-pre1\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+MonoTouch10+Xamarin.iOS10\Xamarin.Forms.targets" Condition="Exists('..\packages\Xamarin.Forms.2.0.1.6492-pre1\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+MonoTouch10+Xamarin.iOS10\Xamarin.Forms.targets')" /> <Import Project="..\packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets" Condition="Exists('..\packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets')" />

    I removed the old 2.0.1 one from the csproj. I had to close VS and re-open and it worked just fine then.

    Monday, June 26, 2017 10:21 PM
  • User150983 posted

    @JamesMontemagno said: So, this one actually has to do more with NuGet and perhaps not removing and updating the csproj file correctly.

    For instance I updated to 2.3.4.247 from an older version and NuGet didn't know how to upgrade and left old busted imports around. Sooo, unload your projects and look into the bottom of all the csproj files for things that aren't correct.

    For instance I had these two lines: <Import Project="..\packages\Xamarin.Forms.2.0.1.6492-pre1\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+MonoTouch10+Xamarin.iOS10\Xamarin.Forms.targets" Condition="Exists('..\packages\Xamarin.Forms.2.0.1.6492-pre1\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+MonoTouch10+Xamarin.iOS10\Xamarin.Forms.targets')" /> <Import Project="..\packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets" Condition="Exists('..\packages\Xamarin.Forms.2.3.4.247\build\portable-win+net45+wp80+win81+wpa81+MonoAndroid10+Xamarin.iOS10+xamarinmac20\Xamarin.Forms.targets')" />

    I removed the old 2.0.1 one from the csproj. I had to close VS and re-open and it worked just fine then.

    I have the same problem but no old imports in my csproj files :'(

    Tuesday, June 27, 2017 12:38 PM
  • User296682 posted

    This thread contains a lot of workarounds but no solution: - Restart VS: Yes I it works but if you need a bunch of work done, restarting applications is not very productive - Remove bin and object files: If this is the problem, why didn't do the Xamarin Build tools that for me? - Install the latest Xamarin update. Yes good idea, and multiply your problems with other problems from new updates.

    Xamarin drives me frequently crazy, every update has its own specific build problems. There is really never been a Xamarin release that let you run and debug without problems.

    Serious guys, this is again a sloppy work of the Xamarin team. Why can't they get this stuff stable. Why don't we all complain a little harder.

    My solution: Restart VS and rebuild. Then you have for a short time no problem. But it re-appears soon. And if you want to be busy with starting and closing applications and moving and deleting files it is a great solution. But if you want to deliver, IT DOESN'T HELP A BIT!

    Friday, June 30, 2017 1:31 PM
  • User130 posted

    @TonyMelony it re-appears?! Can you share your project so we can look into that?

    Share it on this issue or you could email me directly and we can work something out. david.ortinau@microsoft.com

    https://bugzilla.xamarin.com/show_bug.cgi?id=56640

    Friday, June 30, 2017 1:51 PM
  • User224821 posted

    Hi, maybe it is an issue with the version of your android's SDK. Taking into account that the latest plugins and libraries are compiled against later APIs I've managed to solve this problem by updating the Android SDK (or downloading) to API 25 and then setting the project's compiler to target that API. Also it's advisable to restart the IDE (VS or Xamarin studio)

    Hope it helps

    Wednesday, July 5, 2017 8:51 PM
  • User18728 posted

    @DavidOrtinau said: @TonyMelony it re-appears?! Can you share your project so we can look into that?

    Share it on this issue or you could email me directly and we can work something out. david.ortinau@microsoft.com

    https://bugzilla.xamarin.com/show_bug.cgi?id=56640

    Yes, the problem reappears - restarting visual studio and deleting the bin/obj files only fixes it temporarily. The problem ALWAYS comes back. It seems to rear its head if I switch between Local Machine and Remote Machine when debugging UWP.

    I only have one Xamarin Forms folder in my packages folder, 2.3.5-pre6.

    The UWP csproj file format seems to be different than the iOS and Android. The references are different and it doesn't have the Imports entries.

    This issue, combined with Visual Studio locking up because it's "busy" when loading the solution*, is causing a lot of frustration for me today. I'm going to try removing the DebugType parameter from the targets file next.

    *To fix this, I have to end the task and delete the .suo file from the v15 folder. Ugh.

    Sunday, July 16, 2017 2:42 AM
  • User315372 posted

    Any plans to fix this issue? I'm still getting it and while restarting VS and cleaning the solution is a workaround, its a major pain when you have a large solution that takes a while to open and you're 'mid flow' and dont want to stop to restart becuase of this bug...

    Tuesday, July 25, 2017 8:18 AM
  • User227688 posted
    1. Uninstall Xamarin.forms dll from the solution
    2. Delete bin and obj folders.
    3. Reinstall the Xamarin.forms dll.
    4. Rebuild the solution. This worked for me
    Tuesday, July 25, 2017 4:41 PM
  • User299224 posted

    Same issue here. Go to "Manage Nuget packages for Solution" and ensure all Xamarin.Forms versions are the same from there - fixed for me

    Friday, July 28, 2017 11:08 PM
  • User39110 posted

    Just upgrading Xamarin.forms from NuGet for Forms, Android and iOS, it works fine

    Thursday, August 17, 2017 7:01 AM
  • User13348 posted

    Same here, upgrading all projects to XForms 2.3.4.267 resolve the issue.

    Friday, August 18, 2017 11:12 AM
  • User40046 posted

    I ran into this issue today with a netstandard 1.4 forms project. Cleaning the obj and bin folders resolved the issue.

    Monday, August 21, 2017 7:53 PM
  • User346825 posted

    For me it was only to select the right project from the Solution Explorer then run. This error may happen when you have class libraries included in your "solution"

    Wednesday, September 6, 2017 7:48 AM
  • User348144 posted

    Hi all,

    Here's what solved it for me - - In the Configuration Manager (VS 2017 in the "Debug" drop-down aka Solutions Configuration), I deselected the "Build" check mark for the iOS project.

    Keep in mind, I have not yet connected a Mac agent so I have not yet deployed my app to an iPhone Simulator or an iPhone. My guess is that, once I do, I will be able to check the "Build" for the iOS project and will not receive the error.

    Still not sure the primary cause of the error, as I see it is happening to various people for various reasons, but we should not have to clean / delete bin & obj / restart VS to solve this problem.

    Wednesday, September 13, 2017 7:43 PM
  • User280331 posted

    Hello

    I have updated today from 2.3.4.231 to 2.3.4.270 and for each project in my solution referencing Xamarin.Forms I have build error:

    'The "DebugType" parameter is not supported by the "XamlCTask" task. Verify the parameter exists on the task, and it is a settable public instance property.'

    I have tried all of your suggestions posted here, that is: - all solution projects references only 2.3.4.270 version (manually deleted packages directory had reverted only 2.3.4.270 Forms version by NuGet) - multiple VS restarting - manually removing all bin and obj folders from all solution projects

    Error still persists. Any ideas? I honestly always face different problems when updating to ANY Forms release after 2.3.4.231, which is the last version which works for me.

    Regards Maciek

    Sunday, September 17, 2017 7:04 PM
  • User99611 posted

    Same issue as chetszot. I updated from 247 to 270. It does not help to restart, clean, remove obj/bin.

    It works for Android on my PC, but not for iOS on my MacBook...

    Edit: Downgraded to 267 and it worked for iOS again.

    Friday, September 22, 2017 10:50 AM
  • User341826 posted

    there is maybe two instance opened of visual studio, and one of them is already in debugging the x application.

    Tuesday, October 3, 2017 8:24 AM
  • User351687 posted

    Xamarin forms is the WORST thing that has ever happened to me in my programming career. I have never had this kind of frustrating issues while trying to work with other frameworks. And for God's sake this is Microsoft, can't anyone just find a lasting solution to this useless beast that .NET has delivered unto us? Starting from simply creating a fresh page whose boiler template crashes. Yet awa Microsoft people are still looking at the useless thing and it has even gotten to the stage where we now have to start checking out blogs on how to fix the BULLSHIT boiler plate that is automatically generated with FOOLISH errors in it. Can't something ever work for God's sake in this thing? Now we have another stupid issue and the only thing they have to say is that we should delete bin and obj folders and reopen visual studio, or edit Xamarin.Forms.Target document, commenting one line of the useless crap that they gave us themselves which is still not a guaranty that the IDIOT would work. Meehn... i would continue to pray that u guys would get it right one day though, but as for me, this is where I depart from this useless .NET MONSTER

    Tuesday, October 3, 2017 3:38 PM
  • User189 posted

    @RotimiOdu said: Xamarin forms is the WORST thing that has ever happened to me in my programming career.....

    Odd, Xamarin Forms is one of the best things that has ever happened to me in my programming career. As for frustrating issues, sure it has a few but its all OS so you can take a look inside and see what is happing. Plus the community (yourself excluded) is generally super handy towards each other and to helping the Xamarin team resolve any issues.

    Maybe the problem isn't forms, maybe its you? :D

    Tuesday, October 3, 2017 7:50 PM
  • User352549 posted

    @JakeAnstey said: Solved for me: Restarted my Visual Studio and rebuilt.

    This worked for me.

    Sunday, October 8, 2017 3:44 PM
  • User96008 posted

    Previously, above solutions works for me. But today everything does not work, at the end I solved it by unplugging my Android device from USB port and replug again

    Monday, October 16, 2017 10:06 AM
  • User354844 posted

    @ChrisRzepa really really i spent more time to resolve it thanks ???? ???? ?? ??? :)

    Monday, October 30, 2017 1:11 PM
  • User297510 posted

    Setting this up in CI is impossible, don't have the ability to just restart and clean. Keeps messing up in the cloud with the SAME error :(

    Monday, November 6, 2017 11:57 PM
  • User343509 posted

    Colse visual studio and delete obj and bin for all project(Portable,Android,Ios,UWP)

    after open project clean and rebuild.

    Its work for me

    Tuesday, December 12, 2017 7:39 AM
  • User162878 posted

    updating project to use Xamarin.Form v2.5.0.121934 worked for me

    Friday, January 5, 2018 2:35 PM
  • User322337 posted

    @"AnthonyWaters.7746" said:

    @JakeAnstey said: Solved for me: Restarted my Visual Studio and rebuilt.

    This worked for me.

    For me too

    Thursday, February 15, 2018 7:10 PM
  • User342810 posted

    Delete packages and bin, obj for PCL and Droid. open project -> Clean -> Rebuild solution

    Tuesday, March 13, 2018 12:56 PM
  • User330867 posted

    I ran into this problem after updating to XF 3.

    What worked for me was deleting contents of obj folder in both iOS and Android folder and restarting the VS for Mac

    Monday, May 7, 2018 7:18 PM
  • User365995 posted

    This Xamarin excrement is unbelievably bad. Come back DEC - all is forgiven. Your managers may have been completely useless dumb numbskull tarts but at least your hardware and software worked ...

    Thursday, February 14, 2019 8:44 PM
  • User323193 posted

    @princepotemkin said: This Xamarin excrement is unbelievably bad. Come back DEC - all is forgiven. Your managers may have been completely useless dumb numbskull tarts but at least your hardware and software worked ...

    This very constructive reply made me realise that it has been quite some time since I did not have problems compiling and/or debugging XF apps, recent versions are waaaaaaaay more reliable than XF used to be, thumbs up.

    Thursday, February 14, 2019 9:30 PM
  • User189 posted

    Same, and the improvements that came in 3.5 are amazing.

    Thursday, February 14, 2019 9:51 PM
  • User68062 posted

    In my case Stephane has it right, as you would expect.

    I was moving some dependencies around, and some of my projects that had been getting a pinned version of Xamarin.Forms ended up getting an older version. Pinning those projects to the version that they had been getting (via a transitive nuget dependency) fixed my issue. Thanks @StephaneDelcroix !

    Thursday, February 21, 2019 8:56 PM