Antiy-AVL detected Trojan/Win32.Possiblethreat
Bkav Pro detected W32.AIDetectMalware
TrendMicro-HouseCall detected TROJ_GEN.R002V01K523
Trapmine detected Malicious.moderate.ml.score

Heuristic detection. They're guessing based on behavior and machine learning etc. Probably flagged the Opera installer because it's the net installer that fetches Opera's program files from Opera's servers. They probably wouldn't have a problem with Opera's offline package that includes the program files.

Opera's installer is also compressed with UPX to make it smaller. Some engines consider this malicious even when it's not.

Those detections all look like false positives to me.

@sasha12345678909 Try using the offline installer.

@dchalbert Right, this is done by postinst script in .deb packages. Reported issue for this to be fixed.

Are you trying to install Opera on another drive by any chance? Are you running the installer on that drive or your system drive?

If you're trying to install Opera on another drive, what filesystem is on the target drive? NTFS or FAT32/extFAT?

I'd also try to install with the offline package at https://www.opera.com/download#opera-browser to see if you have better results.

Before trying to install again, I'd open up the Windows Task Manager and make sure there are no Opera installer processes running. Then, I'd delete all files and folders in your "C:\Usres\yourusername\AppData\Local\temp" folder. Might be good to clear "C:\Windows\temp" also.

@sgrandin Problem solved. Deleting the main registry entry of that build did it.

I have deleted all versions and installed the latest version.OPERA4.jpg

@bluewizard - - OK - Re-Installed into the Drive/Folder I wanted. All is good.

Thanks for the help. Problem SOLVED.

Bluewizard

@capusottes The screenshots are from the site sync.opera.com, it doesn't show that you are logged in to sync in that new device.
Menu > Synchronize shows that you are logged in?

@capusottes English here please.

@missichicx Firefox allows addons. That's the browser I use for addon capability.

Not sure but I think Opera no longer allows installing extensions from outside of the Add-ons store.