When I open the launcher for minecraft it logs me out every time, and when I go and hit play, Minecraft loads but it says something about "Play demo world" and "reset demo world" instead of single player, multiplayer, and realms. I don't know how to reproduce this problem because it just randomly happened one day. (i don't know if thats what you ment if its not im really sorry)
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We're tracking this issue in MCL-16570, so this ticket is being resolved and linked as a duplicate.
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