So, my friend wanted to play Minecraft on my computer. So, he logged out as me, and logged into his account. No issues there. I then go to log back into my account. I log out, and pick my account from the drop down menu. It may be helpful to know that my account is linked to my Mojang account. When I click log in, it gives me an invalid credentials error. This may be the fact that it tried logging in with my username, and not my email. Not a "game-breaking" bug, but one that would be very helpful if fixed.