Plesase help! I am new to this but I tried logging into minecraft realms today and it came up with "session invalid please try restarting minecraft" I tried restarting logging out im on 1.12.2 i need help, realms are my favuritre!!!

I'm a frequent realm player
I'm on 1.12.2
I tried restarting
I tried "repairing" using minecraft dowlload launcher thing.
I don't know what to do.