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Vsto add-in doesn't load in Office 2010 in Windows 8 RRS feed

  • Question

  • hi,

    I'm testing my existing vsto add-in Windows 8 to check its compatibality. I've installed Office 2010 32-bit in Windows 8 Release Preview 64-bit. As expected, current installer failed to setup the add-in requirements so I installed the files manually. I've

    1) installed VS 2010 tools for office runtime

    2) office 2010 pia

    3) grant the permission for the addin through caspol

    4) set the VSTO SUPPRESSDISPLAYALERTS=0

    When opening MS Word, the error displayed is "An add-in could not be found or could not be loaded". But the add-in files does exist and its registry is pointing to the correct file. The load behavior for my add-in (in COM Add-in) return "Not loaded. A runtime error has occured during the loading of add-in".

    The above steps can work in other windows. Is there any extra steps that need to be done? I'm guessing based from the add-in load behavior, one of the requirements is not met, in this case vsto runtime 3/sp1. But I cannot install the runtime because it requires .net framework 3.5 which does not exist in Windows 8 (but .net 4 exist).

    The add-in(s) were compiled using Visual Studio 2008 and targeting .net 3.5.

    Thank you for any help.


    UPDATE: I've enabled .net framework 3.5 from window features and install both vsto runtime 3.5 and sp1. I still get the same error "addin could not be found/loaded".
    • Edited by eastman2010 Friday, July 6, 2012 7:59 AM new info
    Friday, July 6, 2012 7:18 AM

Answers

  • Ok, finally managed to make the add-in works. Since I installed windows 8 in VM, so I just revert back to original state. Installed .net 3.5 (either on demand or through windows feature) first, proceed to install vsto runtime 3/sp1 and then setup my add-in. voila. It can work.

    On previousl state, I installed office pia 2010, vsto 4 before installing .net 3.5 and vsto 3 and the add-in doesn't work. removing pia 2010 and vsto 4 also doesn't affect anything. Repair vsto 3 but still failed. So I just uninstalled vsto 3 and reinstall again. And the add-in can work. Is vsto 3 and 4 conflicting each other?

    So the existing steps still work. Just for those who develop a vsto 3/2008 add-in must make sure that .net 3.5 is installed first. (at least in the win8 release preview).

    damian, thanks for your suggestion though...

    Friday, July 6, 2012 9:13 AM

All replies

  • try looking with process monitor what is happening on disk and registry when loading your add-in, where does vstor look for files, etc.
    Friday, July 6, 2012 8:17 AM
  • Ok, finally managed to make the add-in works. Since I installed windows 8 in VM, so I just revert back to original state. Installed .net 3.5 (either on demand or through windows feature) first, proceed to install vsto runtime 3/sp1 and then setup my add-in. voila. It can work.

    On previousl state, I installed office pia 2010, vsto 4 before installing .net 3.5 and vsto 3 and the add-in doesn't work. removing pia 2010 and vsto 4 also doesn't affect anything. Repair vsto 3 but still failed. So I just uninstalled vsto 3 and reinstall again. And the add-in can work. Is vsto 3 and 4 conflicting each other?

    So the existing steps still work. Just for those who develop a vsto 3/2008 add-in must make sure that .net 3.5 is installed first. (at least in the win8 release preview).

    damian, thanks for your suggestion though...

    Friday, July 6, 2012 9:13 AM
  • yes, 2 or more vstor conflict with each other, only last one (greatest version number) will work. great it turned out to be such an easy issue.
    Friday, July 6, 2012 9:21 AM
  • So I cannot install both vstor 4 and 3 at the same time? what about vsto 2005? can it exist side by side with either one of those two?
    Friday, July 6, 2012 9:39 AM
  • no, they cannot, but do not worry since there is no point in such situation, side by side office apps also do not support vsto add-ins, only latest suite will be able to load add-ins, so as you see no point really in multiple vstor packages installed.

    Friday, July 6, 2012 10:13 AM
  • my current installer includes a standalone .net 3.5 sp1 which will be installed in Vista and older. Since windows 8 release preview (at least) came with .net 4 preinstalled but .net3.5 is installed only on demand (requires internet connection), and the vsto runtime version depends on .net version, what's the best way to tackle this inconvenient problem?

    Monday, July 9, 2012 1:36 AM
  • i would first try to see if vstor required for specific office version would run on .net available on windows by default. Usually .net framewroks are backwards compatible so program compiled for .net 3.5 should run on 4.0 just fine.
    Monday, July 9, 2012 7:29 AM
  • For this one I can say that my add-in (compiled with vs2008 targeting .net 3.5) does not work in office 2010 in windows 8 without installing .net 3.5 and vstor 3.0/sp1. I've to do further testing on this part..

    I've just installed vs2010. But this has made me more confuse. Even though I set my project to .net 4, this mean older windows will need to be installed with .net 4 to run the add-in , and it means more hassle to the user...

    Monday, July 9, 2012 8:41 AM
  • each office version comes with its own vstor that knows how to load add-ins, etc. Vstor 2010 understands vsto file format used for vsto 3.0 (office 2007) and is capable of loading this add-in. Additionally there is vstor 2010 for .net 3.5 that will work with office 2007 and you can also create in vs2010 add-in that is .net 3.5 bound. So my guess (only guess since i have not yet tried myself) is to develop on vs2010 add-in that will work on office 2007 and 2010 and try it out on win8.
    Monday, July 9, 2012 9:50 AM