Can you open your .glyphs file in a code editor like VS Code and scroll down to that line? Try adding a semicolon on the end of that line of code. If there is one, or that doesn’t do anything, then there might be problems with the surrounding lines of code (maybe a missing bracket or comma).
I’ve just stumbled across a Glyphs syntax highlighter, you can install it within VSCode to help highlight the code structure better. That might make it easier to see any missing characters:
I have a hunch that the slash character is the issue:
try removing it and writing slash instead:
I just did a little experiment on a test file and was able to replicate & fix the problem. I think you may have renamed slash as \ and that caused the issue.
I think the problem was that I imported all my glyphs from Fontself via Illustrator, and I never gave any of the glyphs names, as I thought I’d just name them in Glyphs app.
And rather than typing the glyph name like “Euro” I stupidly put the euro sign € as the glyph name.
in most places you should be able to just type the character in the name field. There where a few places where that would not work. Try the latest cutting edge version to see if you can sneak in a € or \.