Can't login to realms/client

When opening the game I put my username and password in and it will say connecting for a while then this will pop up. not sure what happened, please help

Error message:
Unable to connect. Please try again later. It the problem persists contact technical support. [Blizz technical support link]

P.S.
I tried waiting a while and trying again to same error

Fixed itself, not sure what had happened either way, but now i don't know how to close this topic x.x

Recently I copied the game folder and tried to use it on different pc and got the same message(unable to connect).
don't know what to do?