Export failure: Duplicate definition of glyph class @MMK

Export doesn’t work because of features Glyphs adds in relation to kerning changes I made.

I don’t see any clear way for me to see or fix whatever has gone wrong, where do I find duplicate kerning entries?

Did you specifically define @MMK classes? If yes: don’t. You can reuse those classes in your feature code but they are managed exclusively in the Kern group fields of the grey glyph info panel.

This is fixed in the latest cutting edge version.

I can export an older version of the font, but the one where I’d done all the metrics fixes is still not exporting in today’s cutting edge version. is that one just done for or?

Can you send me the file again?

just emailed it, does that work?

yes, email is fine.

That problem was probably caused by the converting back and forth between .ufo and .glyphs files. But there is an easy fix. In Font Info > Features, find the entry “Prefix” (in the PREFIX group) and delete it.

Hey guys, I have a similar problem mainly caused from the conversion from Robofont to Glyphs. Cyrillic was done previously in Robofont and I am working on extending the Cyrillic in Glyphs. I thought I solved the problem by making the Kerning feature not active and also added a custom parameter “Use Extension Kerning”, the kerning pairs and metrics are there but when the fonts are exported the Kerning is not preserved. Is there a way to make it work?

You probably can remove the manually kerning classes from the feature code. Check if all glyphs have the kerning groups set accordingly. Then Glyphs would write the same classes automatically. That is actually the reason for the error (Glyphs writing the kerning classes itself).