No errors. During Vivaldi startup, AdGuard started and remains active till +/- .5 min when it just pretends to close. When I switch browsers, it appears working.
Having also MacBook available, I tested there. Works until new (custom) filters are added., than same behaviour as on Windows.
Also - I want to code filter that will block AAA records of certain rap only. How?
As of Windows - I think that this is not AdGuard issue; its Vivaldi to be blamed. I may as well be wrong on this.
Is it happening to specific sites or all sites? I'm running Vivaldi right now and it works fine with AG for Windows on every site I've tested. Also tested it on Mac and it works fine there too with the latest AG for Mac nightly build.
What Windows are you using? Any antivirus/antimalware software being used?
For what it's worth, I also use Vivaldi, with standard releases, Windows 10, Adguard desktop and have not reason to believe it is not working. It has prevented me from going to 2 sites in the last few months. I don't get many ads and it claims to have blocked over 27,000 ads and 13,000 trackers. I see no reason to dispute it. Also the little adguard icon sits in the bottom right corner.