Unable to logon to server: Your username or password may not be configured properly for this connection (-12) - FortiClient Error

If you get the error "Unable to logon to server: Your username or password may not be configured properly for this connection (-12)" likewise, there has a few things to check before you connect to the FortiClient in domain environment.

• First of all please check the your login account is in the locked position or not. If it is locked, please contact your IT help-desk to unlock it.
• If your login account is expired from the domain most probably get the above error. Therefor, Please contact your IT help-desk and extend the login account period.
• If your organisation used the custom port number instead of the default, please add it as below.
• Settings - > Edit the Selection Connection

• Tick on the "Customize port" and add the port number