When you use vCenter Single Sign-On and log in to the vSphere Web Client, you cannot log in if the user account is locked.

After several failed attempts, you cannot log in to the vSphere Web Client using vCenter Single Sign-On. You see the message that your account is locked.

You exceeded the maximum number of failed login attempts (three by default). For security, vCenter Single Sign-On locks your account.

If you log in with a user name from the System-Domain, ask your vCenter Single Sign-On administrator to unlock your account.

If you log in with a user from an Active Directory or LDAP domain, ask your Active Directory or LDAP administrator to unlock your account.

Wait until your account is unlocked. By default, the account is unlocked for users in the System-Domain after 15 minutes.