However, I keep getting an errors when synchronizing the project directory – Error in property 'dataAssociation': category cannot be used when using property groups. Error in property 'dataAssociation': Entity/EntityConstraint properties are not supported by pluggable widgets (pluginWidget="true"). Error in property 'dataAssociation': IsPath/PathType attributes are not supported by pluggable widgets (pluginWidget="true").
Open the project directory and then the widgets directory and find the offending widget by removing the widgets and introduce them one by one, or vice versa remove 1 widget at a time and see if the project will now not give you the error in the widget. Once you found the widget, see if there is maybe a newer version in the marketplace or fix the widget or get the original developer to fix the widget.
Erwin 't Hoen
You sould remove custom widget properties from your pluggable widget xml.
Instaed of Entity type use Datasource & remove Category tags from widget.xml.