Troubleshooting Tip: Unable to login to GUI showing error 'Login failed. A valid certificate is required to login.'

[pachavez]

Description	This article how to fix the error 'Login failed. A valid certificate is required to log in.' when logging in to the GUI of FortiGate.
Scope	FortiGate.
Solution	When logging in to the GUI of FortiGate, an error message appears 'Login failed. A valid certificate is required to login.': This behaviour occurs after upgrading to v7.2.11, v7.4.6, or later. The fix is included in FortiOS versions 7.4.8 and 7.6.3. Access the FortiGate CLI through SSH or the console: Technical Tip: How to connect to FortiGate using SSH Technical Tip: How to connect to the FortiGate and FortiAP console port Under system global settings, disable 'admin-https-pki-required'. config system global     set admin-https-pki-required disable end