I went to http://truckersmp.com/en_US/profile/settings and Account Settings to change my Username
I successfully changed it, Then i came back to the Forum to realize that my Username in the forum didn't change,
First i thought it may take sometime for the changes to take place 30 mins past nothing had happened then i
logged out and tried to log back in and was welcomed with this Error, i tried to login and couldn't then i reset my password
then it logged in automatically. And the Username didn't change too.