Posting on the mod's page is a good idea. I'll do that. In the meantime, can anybody tell me what conditions would cause the tool to emit this message? That is, what does MO think is the problem? Or to put it another way, if I assume this message is legitimate, I still don't know what it means. In particular, what is "group 'Main'"? What does it mean to say that a plugin requires selection of a plugin? And what's significant about the "only plugin" with this requirement?