Sudden Invalid point definition

Glyphs has suddenly decided there is a “Problem with file
at line 85872”, an “invalid point definition” and work has had to stop. I attach the warning message and the area of code it refers to (in Sublime Text). Does anybody know of a way to fix this? I would like to avoid losing a few hours of work by going back to a backup


Looks like some invalid values were written for the stem placement. Could you replace the 9223372036854775808 numbers with a replacement like 0? That should let you open the file again, but misplace these hints.

We’ll have a look at what could have caused these invalid values to be written. What version of Glyphs and macOS are you using?

thank you. Glyphs 3.3.1 (3342); macOS Sequoia 15.0.1