I changed my minecraft username and nothing works

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.


Solution 1:

Log out of minecraft completely

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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)