No, Win 7-64 prof, on the desktop an Win 8.1 prof and 10 prof. on the notebooks and almost the same software installed. But however, on the desktop only opera with VPN causes problems and all other browsers installed work fine (IE, Vivaldi, Firefox 64). I had VPN switched on again today and after watching youtube videos for half an hour, Opera ran out of memory, I had to close Opera and switch off VPN and since there are no issues.

Disabling VPN in fact seems to stop the problem on my desktop, but on my notebooks VPN is enabled an works fine without causing "out of memory"-problems.

Exactly the same problem here on my desktop (Win64, i7, 16gb ram) since about December 2016. I switched to Vivaldi until it is fixed. On both of my notebooks (Win 10 and Win 8.1) Opera works fine.