After Upgrading an Existing Project, loading a screen in SL turns the App blank

Question

Hello everybody,

first of all I want to say I find LS amazing! And the HTML Client makes it even better!

But unfortunately I'm running into a problem after upgrading an existing project of mine.

THe project was previously upgraded from VS 2010 to VS 2012 and now I tried the upgrade to HTML Preview 2. THe Upgrade-Report gives me no errors. And when I run my SL App it starts up fine. But if I open one specific screen (a SearchDataScreen) it starts loading and after a while the whole screen turns blank. Not even the navigation is visible any more.

I tried to debug this, stripping my custom code out of the screen... No difference. Every event that contains user code (empty or not) runs perfectly and the screen continues on loading and then crashes.

Is anyone having similar problems? Any idea what causes this? If you'd like the vs solution to take a closer look let me know.

Cheers

Simon

Answer 1

Simon,

sorry to hear that you encountered this issue. 

Can you also confirm that you can create a new (basic) VS2012 LS Application with a simple table and screen (confirm F5 works as expected).  Then upgrade it by Adding Client...and again confirming that the SL Client app still works?  Just want to make sure the basics are working here....

Also are you using any additional extensions in the application beyond the two default LightSwitch extensions?  If yes, can you disable them for this application and try rerunning relying only on the two default LS extensions? 

Also when running, is it the SL Desktop or the SL Web that you are running? Can you switch it to the other SL app type (Web or Desktop) and try again there too?

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Robert Schoen (Microsoft Visual Studio LightSwitch Team)

Answer 2

Hi,

I am facing the same situation here:

When I add a HTML client to an existing LightSwitch solution a prompt is shown that the current solution needs to be upgraded. This process corrupted the solution in all cases. It is a simple LS solution with no additional Extensions other than the 2 default ones. However it runs against MySQL Server (and the enforced SQL Express).

When I create a HTML Client Solution from scratch it work perfectly!

Answer 3

@Stanwell, can you elaborate on what you mean by "corrupted the solution"?  Do you mean that you can't open it in VS anymore or that when you try to run the solution it doesn't work?

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David Kidder | Senior SDET | Microsoft | LightSwitch

Answer 4

Hi Dave,

after I upgraded the solution by adding a HTML client, I save the solution now comprising both the silverlight as well as the HTML client and exit Visual Studio 2012. If I now open the solution again it can no longer be opened so I have to return to the backup.

If I don't leave VS 2012 I get all sorts of weird errors.

If you are interested in the detailed error messages let me know - I can also provide the solution before upgrade via EMail and describe my detailed steps.

Hope that helps

Answer 5

Stanwell,

In regards to the "Corruption" mentioned above that occurs on "reopening of project"...

How are you re-opening the project?  There is a known issue with using the "Most recently used" (MRU) list where it could be pointing to the ".lsproj" file depending on the env settings.   If it is pointing to the ".lsproj" file (review the links), try using the File|Open Project method and browse to the .sln file and opening it directly that way.  Does this work?

Regarding the "F5 and blank screen" after upgrade that was mentioned above.  Let's try a basic scenario and ensure it works:

1.  Start a new Visual Studio instance, and create a new Lightswitch Silverlight project

2. Add a new Table with a single string property

3. Add a "List And Details" screen and Save the project. 

4. Now take this project and complete the Add Client - and upgrade.   This will of course add the HTML Client. 

5. Return back to the Solution Explorer, right click on the SL "Client" node and set it as the "start up client".  

6.  F5 this application and make sure it works.

If this works, can you expand on this above type scenario and detail as simple a repro as possible for me so I can review it here? 

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Robert Schoen (Microsoft Visual Studio LightSwitch Team)

Answer 6

Hi Robert,

both approaches work! I was not aware of the issue with the "Most recently used" list. Should this not be added to the know issues entry by Steve Hoag in this forum? This might help avoiding confusion with the Preview 2.

However thanks a lot to clarify the issue. When I open the .sln file instead of the entry in the "Most recently used" list, it works nicely.

Really looking forward what you guys will deliver around performance (I am experimenting with LS on a Data Warehouse with tables up to 1000 columns) and the HTML client.

Answer 7

Thanks for the followup Stanwell.

Just to confirm and clarify that I understand your issues and "state":

• The "corruption" issue mentioned is NOT occuring when opening the .sln file directly correct?  Yes, i'll talk to Steve about adding it to the list - thanks for suggesting this.
• "Blank screen under F5" issue - were you able to repro this with the basic upgrade steps I mentioned above?    If the basic upgraded app works correctly but your app is still not working, yes, I would be interested in getting the app via email.  You can email me by using my first initial (R) plus most of my last name (schoe) @ microsoft . com

Regarding your comment about the 1000 columns and performance.  Can you email me with your observations that you have for that?  What you are seeing in regards to perf and what you expect it to be for perf for example?

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Robert Schoen (Microsoft Visual Studio LightSwitch Team)