Realms Error: Invalid session ID - Please try restarting your minecraft

This issue keeps popping up when I try and to to the 'Realms' no matter what I do. I can however go to a multiplayer server.

Restarting the game doesn't help
Restarting the launcher doesn't help
Relogging doesn't help
Rebooting my pc doesn't help
Re-installing my mincraft doesn't help
Changing internet connection doesn't help

Does anyone have a single clue what I need to do?

Can't log in with any of my other friends' accounts too, so I guess it's from my side.