Cannot sign in "Unexpected Network Error."

I followed the one instruction to solve this (clear all browser since beginning) and it didn't work.

I went to its Extension page to see if there was a problem. There I discovered something else, when you click on developer's website you are presented with:

"This site can’t be reached
The web page at https://www.surfeasy.com/ might be temporarily down or it may have moved permanently to a new web address."

But if you try the URL in another browser, it works. I am a premium SurfEasy user so I was able to check that SurfEasy works on my phone. It does! So I was able to do my banking and finance stuff in security of VPN. But no thanks to Opera who since 1pm GMT decided to not work.

The day before I couldn't download one 250MB file without interruptions. It was in private browser VPN. Yesterday afternoon and this morning, VPN itself died.