Every time when it is launched the browser creates an additional profile in the folder App \ OperaGX. When it starts the next time, a message appears that an duplicate profile was found in the folder App\OperaGX and must be deleted ("Please ensure that no profile is stored in that location"). Otherwise the browser doesn't run. First I have to delete the additional profile, which is very annoying. The correct profile is located in the Data folder. This bug has been present in several versions. The problem does not occur with the permanently installed version. But I would like to continue using the browser on USB sticks on different computers.
This is fixed in the revision I just posted. You may need to manually move your profile for this update.
Sometimes, the impossible can become possible, if you're awesome!