If you receive a “User account locked” -error message, your accout has probably been locked because of malicious actions detected on that account or because of some other reason. It is for example possible that someone else has been trying to access your account by guessing password and system has prevented further damage by locking account.
This is called automatic intruder lockout, which resets automatically after some time. If you know what is causing this, please fix it and wait few hours for intruder lockout to reset.
It is also possible that your account has been locked because your contract it has expired etc. If and when situation does not get fixed automatically, please contact ICT-Services (or your manager or student services, depending on situation).