Bug 52338 - Unhandled exception - Unknown error in Windows.UI.Xaml.dll
Summary: Unhandled exception - Unknown error in Windows.UI.Xaml.dll
Alias: None
Product: Forms
Classification: Xamarin
Component: Windows ()
Version: 2.3.4
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Jimmy [MSFT]
Depends on:
Reported: 2017-02-06 22:16 UTC by Peter
Modified: 2017-06-20 00:02 UTC (History)
4 users (show)

Tags: uwp
Is this bug a regression?: ---
Last known good build:

Notice (2018-05-24): bugzilla.xamarin.com is now in read-only mode.

Please join us on Visual Studio Developer Community and in the Xamarin and Mono organizations on GitHub to continue tracking issues. Bugzilla will remain available for reference in read-only mode. We will continue to work on open Bugzilla bugs, copy them to the new locations as needed for follow-up, and add the new items under Related Links.

Our sincere thanks to everyone who has contributed on this bug tracker over the years. Thanks also for your understanding as we make these adjustments and improvements for the future.

Please create a new report on Developer Community or GitHub with your current version information, steps to reproduce, and relevant error messages or log files if you are hitting an issue that looks similar to this resolved bug and you do not yet see a matching new report.

Related Links:

Description Peter 2017-02-06 22:16:33 UTC
The error message is "Unknown error", no stack available.

Unhandled exception at 0x00007FFAEA2D682B (Windows.UI.Xaml.dll) in MyApp.UWP.exe: 0xC000027B: Anwendungsinterne Ausnahme (parameters: 0x000001A0CBEE3690, 0x0000000000000001).
Comment 1 Jimmy [MSFT] 2017-03-07 18:35:01 UTC
Are you seeing this with Forms 2.3.4-pre2? If so, does it also happen with Forms

I wasn't able to reproduce this with a new Forms template project, can you also attach a project that reproduces this crash along with any necessary repro steps? Thanks!
Comment 2 Peter 2017-03-08 19:56:30 UTC
I'm using Xamarin for Visual Studio 4.2. I don't know which Version of Xamarin this is. Can I get the Version number from anywhere? 
I can't send you the project because of I'm not allowed to send it to anyone.
Comment 3 Jimmy [MSFT] 2017-03-08 21:21:44 UTC
In the Solution Explorer, right click your project and select "Manage NuGet packages..." and it should list the version of Forms packaged added to the project. If you are using a pre-release version, can you test with version to see if the crash still occurs? 

When is the crash happening, when the app is launched, or on a certain page? Can you attach the debug output[1] as a file to the report?

[1] https://developer.xamarin.com/guides/cross-platform/troubleshooting/questions/version-logs/#Debug_logs_for_Xamarin.Android_and_Xamarin.iOS_apps
Comment 4 Samantha Houts [MSFT] 2017-06-20 00:02:41 UTC
Because we have not received a reply to our request for more information we are closing this issue. If you are still encountering this issue, please reopen the ticket with the requested information. Thanks!