Answer:
Click "Ignore All" after the message appears, and the crash report should open automatically.
As an alternative, you can try to start the crash reporter manually. The executable file can be found in the program directory. For RFEM 6.01, the path is:
C:\Program Files\Dlubal\RFEM 6.01\bin\CrashReporter.exe
This allows you to send us your system information, at least. We will then try to find the cause of the problem and fix it as soon as possible.