On Win11 App stuck once RDP client pop any messagebox

[VShawn]

Describe the bug

After extensive testing and cross-comparison, I ultimately discovered that on the Win11 system, whenever an RDP client displays any message box, it triggers an internal error, ultimately causing the program to freeze.

These message boxes include, but are not limited to, the connection information displayed by the info button(#437) and CredSSP error messages.

last night I have created a minimal test program and launched the remote desktop to the same server with the same settings on both WinForms and WPF on Win11 22H2. The WinForms program successfully displays the CredSSP
error dialog, while the WPF program encounters an internal error and crashes.

here is the CredSSP error messages:

Works Winform

Crasheson WPF

same WPF program works and pop the message box on Win10

Unfortunately, I couldn't locate the cause of the crash, so I'm unable to fix it.

[VShawn]

I guess Win11 has rewritten the implementation of RDP client message boxes (one evidence is different appearance of RDP message boxes in Win11 compared to Win10) and make message box incompatibe with WPF. If that's the case, we might have to wait for Microsoft to address the issue with WPF (which might be long considering their focus on WinUI now).