If you want to fix your regular install:
@watchmyfail First, goto the URL opera://about and take note of the "profile" and "cache" paths. Then, close down Opera and rename those 2 folders so that Opera starts with fresh ones.
If everything is fine then, you know it's an issue with your Opera profile and you don't need to reinstall. Then, you can just continue using the new profile and cache folder and re-customize everything etc. or you can close Opera, delete the new profile and cache folders and rename your old ones back so that we can try something else to delete in your profile folder to try and fix it.
Another option is to just goto the URL opera://settings/reset and reset just your settings to see if it helps. Always best to close down Opera and back up the profile and cache folders first though just in case.