The error "Invalid Session, try restarting your game"

Hi, i got an error when i clicked on realms it showed the error "Invalid Session, try restarting your game", i did but nothing changed. The day before (August 20th) everything worked fine. i tried restarting my mac, switch wifi and switching accounts. everything else (singleplayer and multiplayer) worked just fine. i have not shared my account with anyone and my account seems normal.