When does a VB.NET application periodically record the event name CLR20r3 in the Windows Event Viewer?

The execution environment in which the phenomenon appears is as follows.
OS WindowsServer2016
Project VisualBasic Windows Forms Application
Framework version .NET Framework 4.8

The log looks like the one below.

Failure bucket, type 0
Event name: CLR20r3
Response: Not available
Cab ID: 0

Issue signature:
P1: aaa.exe
P2: missing
P3: 5f48c92e
P4: aaa
P6: 92e69fc6
P7: 2e
P8: 0
P9: System.NullReferenceException

P7: is the method number
P8: is the number of lines of executable code in the method
P9: is the content of the exception
Ildasm.exe (IL disassembler) can identify the causative code,
Now that I know, when is this recorded in the Event Viewer in the first place? I found the information that the app crashed, but this time it is only recorded regularly.

Exceptions other than the above
System.IndexOutOfRangeException and
It has been recorded.

However, those exceptions did not occur at the event viewer log time in the first place,
The application continues to work without problems.
In addition, the causative code identified by Ildasm.exe (IL disassembler)
There are many mysterious parts such as code that should not be executed at that timing.

Also, even if you run the code that intentionally raises the above exception,
Since it is not output to the event viewer log,
It is unknown when this CLR20r3 log is recorded in the first place.

If anyone knows anything, thank you.

  • Answer # 1

    Due to some problem with Windows, the contents of the Windows Error Reporting (WER) file (under the C: \ ProgramData \ Microsoft \ Windows \ WER folder) are repeated.
    It was like the phenomenon recorded in the event viewer at the current date and time of the PC.

    It was repeatedly recorded in the event viewer
    Exceptions have occurred several times in previously running versions of the application
    It seems that it was caused by remaining as a Windows Error Reporting (WER) file.

    After deleting all Windows Error Reporting (WER) files, the log that was the problem this time is no longer output.