Here is, what helped me:

1. Close running Opera
2. Rename folder with profile: "C:\users%username%\AppData\Roaming\Opera Software\Opera Stable" to ".\Opera Stable old" (The "healthy" profile should be "Opera Stable 2, 3,..." depends in what phase of crash you are now - basicly it is the largest folder"
3. Install latest version of Opera from offline installer
4. Close again the automatic-opened failed try
5. Rename folder with profile: "C:\users%username%\AppData\Roaming\Opera Software\Opera Stable" to ".\Opera Stable bad"
6. Create in folder "C:\users%username%\AppData\Roaming\Opera Software" new own folder ".\Opera Stable"
7. Take ownership of folder "Opera Stable old" EVEN if you are owner already
8. Copy everything from folder "Opera Stable old" into your new folder "Opera Stable"
9. Opera should start normally.