Internal server error following update from 13.0.4 to 13.0.5

I allowed to updater app to update my 13.0.4 installation to 13.0.5. Afterwards, on first access attempt an internal server error is shown. Help!

Log file available.

What did you try so far, to solve the problem? Did you check the error messages in your log file?

I was able to solve it, in the end.