Opera VPN doesn't work. This is not the first time.
Internet connection with Opera works with out VPN but not VPN switched on! This started to between days 17-18.5.2017 - Gives this announcement: "Authentication credentials required." or just keeps trying to connect. VPN icon is blue and it's not connecting. Everything with my computer and with my internet connection is working just fine, just not Opera VPN.
My suggestion is: Keep Opera VPN working if you are offering it. It is only reason why I'm using Opera and I believe, so it is with most of the other users.
This is not the first time! It seems, the problem is at the servers.