Hi, I have Glyphs 3 3.1.2 (3151). I used mekkablue’s script for interpolation. The interpolation worked but I couldn’t save my file. The operation couldn’t be completed. -[NSNull length]: unrecognized selector sent to instance 0x2089789d0 keeps coming up when I click CMD + S. Any solve for this problem?
Then you managed to get some invalid data into the document. Not sure if that is resolvable.
Do you remember what you did just before this happened?
Can you check if there is a (autosave) file next to the .glyphs file?
Can you try exporting to .otf or .ufo, just to try to save as much of the latest changes?