Export error from the Core

I try to export a font with a .glyphs file but I have this core error :

(My version of glyphs is 3.1 (3133)). Any idea ?

That means that you have zones that intersect. Maybe the cap height and the ascenders are too close?

That’s right ! how can I fix it ? I have seen this topic… right ? Error export OTF / There are overlapping zones

Yes. The cap height goes to 721 and the ascenders start at 720. So there is an overlap.

OK Georg ! and thanks for your help.