tl;dr at the end So, after returning to Minecraft for quite some time the first thing I wanted to do was hop into ECC again. Well, when I typed something I noticed my name had been changed. Likely the event of someone tapping into my account and changing it in the 3 years I was inactive -lol-. So, like any reasonable person I went onto mojang's account page and changed it back to my rightful name -Sizsizma10- ... Welllllllll now I can't sign into the server anymore and get the message " Failed to connect to the server. Not authenticated with Minecraft.net " Now, I figure it's something to do with the name change. Don't know if I have to wait it out for some reason or if there's something that isn't matching up in the files on your end that is preventing me from signing in. Either way I figured I'd post this in hopes of getting it resolved faster just in case tl;dr: Signed in. Username got changed while I was inactive. Changed it back to original (Sizsizma10). Can't connect now.