Releasing the new adblock in Opera appears to have been a mistake.
Let's be honest we all use adblocks mostly for Youtube.
After updating Opera, I briefly turned on the new adblock, even though I already had uBlock Origin.
The result is "an error occurred please try again later" error. It goes away after 2 or 3 refreshes, but still annoying.
What do?

@leocg Bookmarks.adr it is indeed. Thank you, you were very helpful.

I've been using Opera for a long time.
I remember there was some new Opera version introduced, that changed everything, including bookmarks. On installation, the old version was not deleted and the new Opera had empty bookmark list.
For several years afterwards, I had 2 Opera versions, the new one and the old one (it could have been 11.64, I'm not sure). The new one was for browsing and the old one just to access old bookmarks.
Few years ago, this old Opera abruptly disappeared after update and every attempt to open it resulted in opening new Opera instead.
I still have the same HDD and Windows. Is it possible to access this old Opera version? Mostly i'd like to recover old bookmarks. I miss some songs I liked back then
Thank you.