"No mapping between account names and security IDs was done" error recieved

Hi
I tried changing the account name through control panel and now when trying to get back into control panel its giving me the error "No mapping between account names and security IDs was done"

can someone please help me??

thx!

You just need to restart.

This happens when you change the username so when the system tries to authenticate it hasn't finished changing the username on the security ID.