Dispatcher stops working with hanging in NtUserGetMessage

[BenSchoen]

• .NET 4.8
• Windows 10 Enterprise LTS 1809
• WPF

Problem:
Our wpf app sometimes freezes and everything is "disabled". The issue is very random and not reproducable. Usually it happens once a day and not every time in the same context. The dispatcher is on executing NtUserGetMessage and there is no usercode blocking the dispatcher. Installing a newer windows version made the issue rarer. The application background stuff is working further.

I am unsure if its really a bug inside wpf. Are there any suggestions to debug the issue further or is something similar known?

[lindexi]

It stops in NtUserGetMessage as expected. WPF application will receive the windows message by GetMessage. It is stop in GetMessage when the application is idle.

[BenSchoen]

Ok, got it. What could be the the reason for a not responsive visual. In this state of the callstack all buttons are disabled, including those, which are enabled all the time.

[vishalmsft]

@BenSchoen As this is a question, I am moving this to Discussions->Q&A.
As you said, installing new version of Windows made the issue rarer, hung issue may be due to other reason.
Have your tried it on more than one machine?