Hi, I am working on a Hebrew font in Glyphs Version 3, and once I started kerning it does not let me save the file. I get this message:
What does it mean
Glyphs 3 handles right-to-left kerning diffrently to Glyphs 2. The error message tells you that the Glyphs file you are working on is format 2, but that the kerning changes you made require the file format to be format 3.
You can switch the format to version 3 in “File” → “Font Info…” → “Other” → “File Saving” → “File format version”. This will convert the file to format 3.
Worked like a charm. Thank you! 
