This may happen usually for exceeding the limit of wrong password login trials by the administrator. Sometimes this occurs when an administrator did not log out properly from the Smart Console for any reason - his/her PC crashed, connection to the Smart Center was lost, etc. No worries, it is easy to fix, go to the command line of the Smart Center, then (if not already) into the expert mode and type:
fwm lock_admin -u <account name>