Same problem here. This can’t be coincidence. If this many people are having problems with YouTube — and only YouTube — then it’s a “them” problem, not a “me” problem. To be sure, I’ve done every possible fix including a couple factory resets. But still the same ugly error message when i try to launch YouTube TV or YouTube. Screenshot below.
i have a 4670x Ultra with 11.0.0.
Figured it out by reading the answer on Reddit. Reboot your modem and router. Just that simple, but the only thing i hadn’t tried.
if you want to confirm this solution before actually doing it, try connecting the Roku to another network (like the hotspot on your phone) and see if YouTube works. If it does, then do what I said.