You don't just get rid of it. I don't know how much you know programming, but you would have to change it in html / css eg with your own plugin, or wait for a new opera update hoping they will change it.

No, I haven't found any solution. Sometimes this error occurs when logging in. I log in until it is done.

Someone uses a plugin to download videos from vimeo. Can someone recommend one to me that will work?

I have a problem logging in to the forum, I often get this error

Internal error.
Oops! Something went wrong.
/auth/opera/callback
Failed to obtain access token