I don’t believe anyone mentioned this yet so… here goes nothing, there is a suspicion that this is due to A/B testing

This is a bug report from the Invidious project; this is back in June 6 (so four months ago), but the hoster of a fairly large instance noted a very bizarre error message on the Invidious project…

Conclusion is that Youtube is very likely rolling out A/B testing of requiring all clients to login before viewing videos

Refreshing will probably work considering this is most likely result of an A/B test, but unfortunately I don’t see a way of this problem going away