Not sure, but you can try this if you want:
Goto the URL opera://bookmarks and export your bookmarks just in case.If you want to backup your opened tabs, right-click on a tab and choose "save all tabs to a speed dial folder" first. Then, if anything happens, you can import your bookmarks back in. Then, you can right-click on that speed dial folder and choose to "open all".
If you sync your passwords, goto the URL opera://settings/passwords, click on the kebab menu (3 vertical dots) to the right of "Saved Passwords" and export your passwords to a CSV file.Then, if you ever need to import your passwords, goto the URL opera://about, take note of the "install" path and close Opera. Then, open a command prompt and run:
"C:\Program Files\Opera\launcher.exe" --enable-features=PasswordImport(adjust the path to launcher.exe to what opera://about says).
Then, you can goto opera://settings/passwords in Opera and use the same menu to import your passwords back in. Then, you can close Opera and close the command prompt and open Opera from its icon.
Goto https://sync.opera.com/ and reset sync.
In Opera, sign out of sync if it says you're signed in.
In Opera, goto the URL opera://about and take note of the "profile" path. Close down Opera and use Windows Explorer to goto the profile folder. In the profile folder, delete the "Sync Data" folder.
Start Opera and set up sync like you never set it up before.