Down the login part of the boot screen, there is a bar saying "Username" and "password". But when we put our Minecraft Usernames in it and our passwords it says: Mojang account, use e-mail as username.
It would be easier if the bar was named "e-mail" instead of "username"...
MCL-334
Username bug in Launcher
Resolved
Invalid
0
Some people do log in with their username. Unless you are logged in, Minecraft can't possibly know which one to use.