How to fix this error message

hello everyone!
I have an error pop-up message when I am trying to save my font file. It showed up first after I inserted instances between masters. Now I cannot save the file because this message comes up:
Screenshot 2024-11-04 at 15.03.30

Can you try to remove the instances again?

I removed them, but now if I try to reinsert them, the Insert button doesn’t do anything

I’m sorry, it does – but the instances are not shown in the Exports window, just in the preview window (below)
after this, the same issue comes up, I am not able to save the glyphs file.

can you run this in the Macro windo?

Font.instances = None

nothing happens, the instances are shown and i cannot remove them

Can you you save?
And can you check the latest autosave file (it should be next to the .glyphs file)?

I cannot save the file, when I hit cmd S, this error message comes up and the file isn’t saved. Glyphs asks if I want to quit without saving the file but I cannot save.

Can you check in Finder, if there is a “(autosave).glyphs” file next to your file?

And what version of Glyphs do you have?

No, there isn’t any autosaved file. I have Glyphs 3.2.3

Sorry guys, do you have any idea how to solve this problem?
Unfortunately, I didn’t get any further with the solution.

I don’t think I can debug it any further without seeing your machine. But I don’t have much time in the next couple of days for a screen call.

Can you export the font to .otf (disable the remove overlap). That should preserve most of the info in the font. So you could rebuild if from the otf.