Thanks for the help.
In fact I did do all of the above 2 or 3 times.
When we found Hulu's error would go away, we power cycled the cable modem, router, and pulled the roku stick and usb out of the TV in question. No changes.
Then we found that Peacock also wouldn't play content. We just have a free account but have enjoyed some old series TV on there.
Last night I found this to clear the Roku cache:
Select Home on the main menu.
Then, on the remote controller press Home 5 times + press Up + press Rewind 2 times + press Fast Forward 2 times. It should take a few seconds to clear the cache.
Seemed to reset roku, but didn't help.
After trying that, I even tried my youtube accnt (also free) under roku and it gave me a license issue on a free with ads movie.
The only final option I have is the hard reset of Roku and redoing the channels I want one by one. If that doesn't work I'll have to get a new device. Hate to give Roku any $$ for failure on their part.
Perhaps an upgrade deal is available. I've been meaning to complain anyway since this remote uses batteries at an alarming rate, ~$10/month.