This is on personal experience so I don’t know if this is a very good method to use. The reason your account was expired because the day you created it, it said “You have 48 hours to verify the email and if you did not verify the email your account will be deleted”.
Once you get this message do not accept it by pressing any button, quickly go to your email where you created your Myplayer account and go to the message says Do Not Reply then verify your email. Once your done, close application and it should work.
NBA 2k19 