Glyphs file fails to open

When opening it states: “The document could not be opened. Problem with file at line 37941” … I also tried Opt-Shift opening, but it also fails.

I’m running Glyphs 3.0.4 (3098) on MacOS Mojave 10.14.6

I had just duplicated a single master, and I suddenly noticed the lowercase ‘a’ somehow had become incompatible (I hadn’t even made any changes to the duplicate). I thought it’d be a bug, so I shut down Glyphs to reopen the file, but it’s now stuck on the error notification.

Can you open the .glyphs file in a text editor (e.g. Textmate or Sublime Text) and check what you find at line 37941?

unicode = 54;

And the few lines before this?

closed = 1;
nodes = (
width = 307;
metricLeft = //O;
metricRight = //O;
unicode = 54;

Remove the two lines just above the Unicode line.

Thank you, I can open it now!