Technical Tip: Getting error 'Failed to add user <username> due to reason(400):'Auth Client' when enabling Two-factor Authentication with FortiToken Cloud

[achu]

Description	This article describes that when enabling Two Factor Authentication to a FortiGate administrator, the 'Failed to add user <username> due to reason(400):'Auth Client<FG Serial #>/#FOS_Administrator) was not found' appears. Note: The FortiToken Cloud trial license has already been enabled and verified following the related document. DNS and connectivity to the FortiToken Cloud server have been verified as well.
Scope	FortiGate.
Solution	Enable 'Auto-Create Auth Client (for FOS only)' from the FortiToken Cloud portal. To access the FortiToken Cloud portal From the FortiGate Support portal: Go to Services and under Cloud Services, select FortiToken Cloud. From the FortiToken Cloud portal: Go to Settings -> Global, enable 'Auto-Create Auth Client (for FOS only)', and apply Changes. After enabling, it is possible now to create or modify existing administrators to use two-factor authentication with FortiToken Cloud without any error.   Related articles: Technical Tip: How to provision FortiToken cloud Troubleshooting Tip: 'Failed to retrieve FortiToken Cloud status'