Please be advised that the Vision 3 Release DLM 820 reinstates the Login Retries and Lock out user when login failed “retries” times options available from Management Tools - Security - Security Settings:

This means, if your practice has a tick in Lock out user when login failed “retries” times your staff are locked out of Vision 3 if they reach the Login Retries number.
Once the number of failed logins is reached, a member of staff must be ‘unlocked’ by a System Administrator.