It's odd I can't replicate this issue at all, however I made a small patch to prevent this error from occuring. I hope this should resolve the issue if not I'll take another crack at it.
You're using this plugin on mz? or mv?
edit: nvm lol read your comment below, my apologies for that I tested on MZ not MV however the patch should resolve the issue regardless, if it doesn't though just let me know! :)