Hi @anasyrma, check if "opera://settings/content/protectedContent" is enabled and if not enable it, and see if this helps.

If it doesn't, try to launch the Opera with the switch as shown below (changing user agent string - add it at the end of the shortcut you use to run it):
"\path\to\launcher.exe" --user-agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.85 Safari/537.36"

If it still changes nothing, you can check one of the other tips mentioned here.

I got around this error by logging into my Opera account in Chrome or another browser, then link your google account to your opera account.

Most probably you were using an extension, Opera Chromium never allowed the user to change the position of tab bar.

If your software manager has "additional repositories" you can add Opera so it will update with:

deb https://deb.opera.com/opera-stable/ stable non-free #Opera Browser (final releases)

What is Opera's OS? What is the problem?

@concretable

Delete metadata folder from unzipped pack. Also remove possible update url from manifest.JSON.
Deleting metadata makes sure that Opera uses only your local files.