@benedikt said in Traceback when sorting AllFonts(): fontParts.world.FontList these functionalities should be provided by an implementation and not by fontParts, similar to CurrentFont, CurrentGlyph, CurrentLayer, CurrentContour, CurrentPoint,... FontList is optional but could be provided by an implementation.

Thanks so much Frederik! That's exactly what I was missing!

this is a known issue and already being fixed in one of the embedded packages: see https://github.com/typesupply/defcon/commit/bce898c1c2e6b24c4774fe9ca6f7a9f5b80ed6a0 this only happens with open contours... an update is scheduled soon