Since the latest update (27.07. - 21.0.0.88998) I can´t challenge any friends anymore. I am told to return to the main menu, although I am already there.
Most likely explanation is that one of you two already upgraded to the new patch and the other did not yet. Probably as a result of you playing on different platforms, where the patch is not pushed at the same time.
You can only challenge players that are on the same patch as you.
Both are playing on PC having installed the new update (same version) - never had that problem before.
Both are getting the same message when each want to challenge the other.
I have the same issue. We do daily lobbies and it’s been a day. I was the only one who couldnt be invited yesterday. I figured lets try tomorrow. Same thing today. I cant challenge anyone and I cant get challenged by anyone. They can all challenge each other.
Same here can t Login again since the new update
I´ve checked using the same Account on 2 other PCs. One has the same issue, on the second PC it´s working.
I´ll try if a fresh installation of Hearthstone will solve the problem.