The extension is now almost unusable for me. I keep getting this message: "Permission to inject a script was denied on..." It's just frustrating, but not very helpful.
Sorry for the inconvenience. Previously, when Firefox wouldn't insert the necessary script, it just failed silently. I kept that as an option if you preferred that behavior.
But more generally, Firefox 128 finally allowed injection into most non-Mozilla sites. If you are running an older version, such as the Extended Support Release of Firefox 115, you could consider upgrading if your OS can run Firefox 128 ESR.
