We’ve recently noticed a number of cases where vSphere administrators become locked out of their accounts or receive reports of incorrect passwords in the vCenter Server Appliance. If you find yourself in this position, here are two articles that address these issues:
When attempting to log into the VMware vSphere 5.1, 5.5, or 6.0 Web Client you observe the following symptom: “User account is locked. Please contact your administrator.” This often occurs if the wrong password was entered multiple times. Waiting the default 15 minutes lockout period will allow to attempt the login again. If after multiple attempts, you are still not successful, you may need to reset the password.
When attempting to log into the vCenter Server 5.5 and 6.0 Appliance, you experience symptoms where the root account is locked out. This often occurs because the vCenter Server appliance has a default 90 password expiration policy. Steps on how to modify the password expiration policies and to unlock the password.