@unidownloader: I have the same problem, also OperaGX. Last opera version, just updated. Extension doesn't want to even start 😕
Probably this is a OperaGX problem, because everyone is saying that the extension is good.
Explaining the main problem:
After installing an extension, it does appears on extension page, but it is gray. I can't click on it at all(
Hopefully you will fix that 🙂