For a specific player, I appear to be allowed to challenge them (they are blue and have an active challenge button) but when I press the challenge button and press the “yes, I really want to” button, then I get a 500 error telling me they can’t be challenged…
This is not universal, just one player so far.
Is it someone you recently played against? I can’t remember the message for that scenario.
It is in fact someone I played recently, yes.
The message was a ‘500’, which generally means “The server wasn’t expecting this sort of thing to happen”.
Is this a “known scenario”? Is there some rate at which you are not allowed to challenge people again?
Yes but I can’t remember the details. Sorry.
[Edit] Here it is: Ladders · online-go/online-go.com Wiki · GitHub
Within 7days of finishing your previous game with them.