MakeOTF syntax error prevents exporting

Recently, whenever I export my font, this error message has come up:

MakeOTF error
Error: “syntax error at “Udieresisgrave” [features.fea 33” in Class Uppercase in line: 1

I ran generateFont.command as recommended here, but that didn’t result in any error related to this issue.

What is the problem here? My Uppercase class looks normal as far as I can see.

Look at the spot the error points at and immediately before. Mistyped something? Superfluous bracket? Non-ASCII character? Invisible character? Can be anything.

Thank you! That worked.

What exactly was it in your case?

EDIT: I updated the Troubleshooting tutorial.