CODEWITHSUNDEEP
c#wpfvisual-studio-2015
Jason
Jason

Reputation: 13986

LoadFromContext Occurred

I have a very simple C# problem that loads a Windows WPF window from a library. Here's the code:

public partial class App : Application
{
    public App()
    {
        MainWindow mainWindow = new MainWindow();
        mainWindow.Show();
    }
}

But when I run it breaks on the mainWindow.Show(); line with the following error:

Managed Debugging Assistant 'LoadFromContext' has detected a problem in 'C:\Users.....\bin\Debug\Test.vshost.exe'.

Additional information: The assembly named 'WpfXamlDiagnosticsTap' was loaded from 'file:///C:/PROGRAM FILES (X86)/MICROSOFT VISUAL STUDIO 14.0/COMMON7/IDE/COMMONEXTENSIONS/MICROSOFT/CLIENTDIAGNOSTICS/XAMLDIAGNOSTICS/x64/WpfXamlDiagnosticsTap.dll' using the LoadFrom context.

The use of this context can result in unexpected behavior for serialization, casting and dependency resolution. In almost all cases, it is recommended that the LoadFrom context be avoided. This can be done by installing assemblies in the Global Assembly Cache or in the ApplicationBase directory and using Assembly.Load when explicitly loading assemblies.

The MainWindow class just extends from System.Windows.Window; I'm not exactly sure what this means and how to solve. Just upgraded to Visual Studio 2015.

enter image description here

enter image description here

If I ignore the exception and continue I get this when I close the last window:

enter image description here

Upvotes: 31

Views: 16484

Answers (4)

Tawab Wakil
Tawab Wakil

Reputation: 2323

Visual Studio creates a number of hidden files and folders within your solution that can stagnate over time and cause issues including the LoadFromContext error. Try closing Visual Studio, deleting the following files and folders, and reloading the solution:

  • .vs (folder)
  • *.suo
  • *.user

You may wish to back up anything you delete, but Visual Studio will regenerate these items automatically as needed.

Upvotes: 1

Andy Braham
Andy Braham

Reputation: 10171

I all of a sudden started seeing this error in VS2015 and fixed it by opening the "Exception Settings" Window (CTRL + ALT + E) and press the "Restore Settings" Button :

enter image description here

Upvotes: 23

Denis P
Denis P

Reputation: 615

In VS2015 I am getting two exceptions from WpfXamlDiagnosticsTap.dll

  1. The first one is "LoadFromContext" and it occurs when activating the first window.
  2. The second one is "NotMarshalable" and it occurs when closing that window.

Simply ignoring those two Exception types allows me to run the application, and use the UI Debugging tools. I haven't observed any adverse effects.

Upvotes: 3

M. Altmann
M. Altmann

Reputation: 726

I'm running into the same issue after switching from Visual Studio 2013 to 2015. Some old projects (WPF, .NET 4.5, MVVM Light) produce this error - other not. In visual Studio i can skip the exception but newly created releases stop while loading and try to open the JIT Debugger.

Until now the only solution seems to be a rollback to Visual Studio 2013.

** UPDATE **

Finally I solved it in VS 2015 by unchecking the following option:

Tools –> Options –> Debugging –> General –> Enable UI Debugging Tools for XAML

Upvotes: 44

Related Questions