OS X 10.11.1, G2 2.1.1 [807]
I try and export a font I finished months ago as a UFO and get this error message:
“Something went wrong while exporting: *** -[__NSArrayM insertObject:atIndex:]: object cannot be nil”.
It exports just fine as an OTF font. It doesn’t cause Glyphs to crash, so not Crash Report.