I too am unable to use this very useful plugin anymore. I think the problem with this plugin is probably related its being incompatible with the current API, i.e. it was probably written against the deprecated API. If that is true, I suspect that the plugin will not be usable by anyone who has a current version of Joplin until someone rewrites the plugin. That, sadly, is well beyond my ability.
See this discussion on this forum for more information on the API issue.