Will look int0 the error. I do not have an 8.1 to test on, but I do have a Virtual Win 10 installed. Will look for similair error on there.
Ken
Just some further info on the error message:
another small popup window appears ("Microsoft .NET Framework" as title)
In German, it says: "Unbehandelte Ausnahme in einer Komponente der Anwendung. Wenn Sie auf "Weiter" klicken, ignoriert die Anwendung den Fehler und setzt den Vorgang fort. Die Datei wurde nicht gefunden."
English translation: "Unhandled exception in one of the componentes of the application. If you ckick on "next", the application ignores the error and continues. File was not found"
Maybe the last - "File was not found" is a good hint, i.e., something in the directory system of MC20 for the skins & views was simply changed?