The new beta (version 1.1b31) for Max 8.1.4 (and higher) and Ableton Live 10.1 (posted on July 09, 2020) no longer requires a license update and also works with MacOS Catalina:

Version 1.0b27 for Max 8 and Ableton Live 10 (posted on July 21, 2019)

Your license expired this September. To continue to use this version of MaxScore, please...

... and follow instructions in the readme file. You need to do this even after re-installing this MaxScore version.