UWP app reports 'application busy' system exception in COM call

Jos Huybrighs 336 Reputation points

I have a DesktopBridge app (UWP app with a win32 process launched from the app) published to the Windows Store where I see now and then crashes in MS AppCenter.
The crashes occur inside a COM handler and seem to indicate that there is some kind of deadlock.
How can I find out what is actually reporting the deadlock? I see in ms appcenter an IID (49A07732-E7B8-5C5B-9DE7-22E33CB97004) for a COM call but I have no idea what this COM call would be.

This is the exception I see in ms appcenter:

System.Exception: The message filter indicated that the application is busy. A COM call (IID: {49A07732-E7B8-5C5B-9DE7-22E33CB97004}, method index: 3) to an ASTA (thread 7668) appears deadlocked and was timed out.

This is the stack (reported in ms appcenter):

System.Runtime.InteropServices McgMarshal.ThrowOnExternalCallFailed (Int32 hr, RuntimeTypeHandle typeHnd)
f:\dd\ndp\fxcore\CoreRT\src\System.Private.Interop\src\Shared\McgMarshal.cs at 1189:13
__Interop ComCallHelpers.Call (__ComObject, RuntimeTypeHandle, Int32)
__Interop ForwardComStubs.Stub_10[TThis] (__ComObject, Int32)
Microsoft.AppCenter.Utils ApplicationLifecycleHelper.<ctor>b__17_1 (Object, UnhandledErrorDetectedEventArgs)

The stack doesn't show any code I have written.

How should I interpret this stack and how can I find out which code in my app is causing this? Is the IID of the COM call known?

Appreciate any help!

Universal Windows Platform (UWP)
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