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...download zipped file
... and follow instructions in the readme file. You need to do this even after re-installing this MaxScore version.
The new beta (version 1.1b4) for Max 8 and Ableton Live 10 (posted on October 20, 2019) no longer requires the license update:
MaxScore / LiveScore requires Java.