Error by exporting VF

Hi! I´m geting the following message by VF export:

There was a problem writing the file

Subtable Overflow: tableType: OTGPOS LookupIndex: 6 SubTableIndex: 0 ItemName: lookupList ItemIndex: 0

How can I fix that?


Internally an OpenType consists of so-called OpenType tables. One of them, the OT GPOS (=‘OpenType glyph positioning’) table is too big (‘caused an overflow’). The GPOS table contains information about (re)positioning glyphs, like kerning, mark attachment, these kinds of things. In Latin fonts, that usually means that there is too much kernings, or too many exceptions with large kerning groups.

Solution: Either reduce kerning, or add the Use Extension Kerning parameter to File > Font Info > Font > Custom Parameters. Or in the case of a Variable Font, it can be helpful to reduce and sync kerning exceptions between masters.


Cool the custom parameter works!