Variable font export won’t work

I was able to export files previously but it won’t export now.
It says that it can’t convert to compatible TrueType curves.
All characters interpolate successfully across all weights and I’m not seeing anything abnormal between or within masters.
I’m working on the latest cutting edge version

Any idea how I could solve this problem?

Can you find out which glyph causes the problem?

There are several. The only one that I know doesn’t cause a problem is the capital G.
And I took one of the “problem glyphs” the f and I’ve revised all paths, nodes, etc. and they seem alright

You can add a Enforce Compatibility Check custom parameter to the font. That will give you a better overview. Then this https://glyphsapp.com/tutorials/multiple-masters-part-2-keeping-your-outlines-compatible should help.

With the Enforce Compatibility Check Parameter I now see the incompatibilities.
Thanks.

I have another question.
Now I can see that some of the nodes are not in the same order through out the masters. What is the best way to fix that?
(Example for one of the nodes thats incompatible)

The first master has only straight lines. You need to make the corresponding segments all curves.