Originally posted by another user
Now that some services of the PlayStation®Network are back up, as a security measure, a process for all customers to change their PlayStation®Network account passwords has been added. If you attempt to sign in sign to the PlayStation Network from your PSP system, you may receive one of the following error messages:
-An error has occurred.
-An error has occurred. You have been signed out of PlayStation Network.
If any of these messages are displayed and you cannot sign in to PlayStation Network, you must change your PlayStation Network password as follows.