I recently changed my Minecraft username through mojang, and everything was good. Then I opened minecraft from my desktop to mineplex, and this showed up:
Not authenticated with minecraft.net
Please help. I already tried restarting my minecraft, refreshing, and logging out and in.
Best Answer
Log out of minecraft completely
If this doesn't work try deleting .minecraft and completely reinstalling Minecraft (I suggest first making a backup of servers.dat, saves and resource packs)