Issue with path when generating instances

[LettError]

Generating instances by hitting the Generate Instances button in the instances tab.

Traceback (most recent call last): File "lib/doodleDelegate.pyc", line 90, in sendEvent_ File "/Applications/RoboFont_4.5b.app/Contents/Resources/lib/python3.12/vanilla/vanillaBase.py", line 539, in action_ self.callback(sender) File "/Users/erik/Library/Application Support/RoboFont/plugins/DesignspaceEditor2.roboFontExt/lib/designspaceEditor/ui.py", line 1497, in instancesEditorGenerateToolsCallback GenerateInstanceSheet(self.w, self.operator, instances) File "/Users/erik/Library/Application Support/RoboFont/plugins/DesignspaceEditor2.roboFontExt/lib/designspaceEditor/ui.py", line 253, in __init__ instanceDescriptor.path = os.path.abspath(os.path.join(os.path.dirname(self.operator.path), instanceDescriptor.filename)) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "<frozen posixpath>", line 90, in join File "<frozen genericpath>", line 164, in _check_arg_types TypeError: join() argument must be str, bytes, or os.PathLike object, not 'NoneType'

[typemytype]

I guess here the instance.filename is still None, dont know how this happens, every new instance will or when the filename attribute is None a new file name is generated based on the prefs, family and style name