Too many kerning pairs

[GeorgSeifert]

Technical background: Each pair in the "kern" table takes 6 bytes, there is a 14-byte header, and the maximum size of a subtable is 64K bytes, so (65536-14)/6 gives you 10920. Most font engines only support a "kern" table with one subtable, so there's the limit.

Glyphs does not export a kern table. It exports a kern feature in the GPOS table. The biggest difference is that the kern feature support classes that can reduce the number of needed pairs.