When I try and use the (beta) extension with the newest version of vivaldi, I get an error about "can't accept a connection from your browser".
https://dl.dropboxusercontent.com/s/8u2x26r8d0bx6z9/2017-06-16 at 9.26 AM.png?dl=0
Version 6.8.BETA-5 (680005)
Vivaldi 1.10.867.38 (Stable channel) (64-bit)
OS Mac OS X
I hope your don't mind, I've moved your reply into it's own thread as it is a slightly different topic. It sounds like your hitting a known issue with Vivaldi. Please check out this announcement on our Mac Beta section of our Forum for a workaround.
Let me know how that goes and if you've any questions about anything above don't hesitate to send a reply.
Sounds good, thanks!