Instance.generate() errors

Scripting
1

Running the script:

for instance in Glyphs.font.instances:
        instance.generate(FontPath = exportFolder, Containers = [PLAIN, WOFF2])

Glyphs.showNotification('Export fonts', 'The export of %s was successful.' % (Glyphs.font.familyName))

(from the docs)

gives the error:

  File "GlyphsApp/__init__.py", line 4861, in __Instance_Export__
objc.error: GSNotImplemented - 111 -[GSBezStringPen addComponent:transformation:]
2

Can you send me that .glyphs file?