I dont know what (Restart the launcher) means. HALP!

I had this problem also. To fix, you need to close the Client, but not the launcher. Press your nickname in the top right corner and press "Log off". Log back in afterwards.
EDIT: Awaiting response?

It can also be fixed via closing and then opening again the launcher (which is what "restarting" actually means)

so, SunCat, thanx for the help. I now am a really pro in Minecraft now.

p.s. im not the german