'Altobere', please explain how the action "Shorten filenames to 64 characters" did work for you in earlier versions of Mp3tag than today.
For what purpose did you apply this action?
Can you give an example input string and the result string by this action?
What did you try?
What should be a positive result?
See also...
42 character field length instead of 64
DD.20110807.1008.CEST