Yes, my Windows have all latest updates, and I don't use any anti-virus software except bundled with Windows 10.

Even more!
When I boot my Windows 10 in safe mode, Opera 44 started load https sites without warning!
After reboot in normal mode, it's still doesn't loading any of https sites.
Date is correct.

After update to 44 Opera do not loading https sites at all. It says:
"You attempted to reach translate.google.ru, but the server presented an invalid certificate."
But all other browsers work! Including Chrome.
What happens with Opera? Why 43 stable version loads https sites, and 44 beta are not in same time?