Arabic VF Export Error

while I trying to export the file I got this error:

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

the typeface has many kerning groups and it has large amount of glyphs

I have already tried adding use extension kerning parameter to custom parameters in font info
and I have checked that blue Botton Screen Shot 2021-10-29 at 6.39.32 AM

what do you suggest me?

I you have the custom parameter already, i fear that you can’t do much others than reducing the kerning pairs.

Could you send me the file, that I can have a look?