Troubleshooting Tip: LDAP connectivity fails with error 'This field is required' after upgrade to v7.4.9

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Description	This article describes how to troubleshoot LDAP connectivity failure after an upgrade to v7.4.9.
Scope	FortiGate v7.4.9.
Solution	In this case, the LDAP server configuration is done, and the password is stored. This saved configuration is verified to have password encrypted.  However, on validating the configuration again in the GUI, the error 'this field is required' is received. In the command line, it is observed that on selecting OK the password gets deleted. Before going to LDAP and selecting OK: config user ldap     edit "LDAP"         set server "192.168.223.64"         set source-ip "192.168.0.125"         set cnid "sAMAccountName"         set dn "dc=testgroup,dc=com"         set type regular         set username "administrator@testgroup.com"         set password ENC s4FRVX3GoJT79LSta3wprZFqRV2Ij0/Fr7l0YBsULQ7GALhcTS2I6cv4kYSGmCtVBAVMm9wlJ x0cnnW/F6W6VMD8QwdPzen9yImY8hxhrxGAVPEPooWIYSwCvt91z4Tvyq2/M85RejLSFXACb+1KaAw8P0PHTO8/ ViNePGMoY/Y8LnEZ3Vi7YvI8KLmx1yx+rZffNllmMjY3dkVA end After going to LDAP and selecting OK: config user ldap     edit "LDAP"         set server "192.168.223.64"         set source-ip "192.168.0.125"         set cnid "sAMAccountName"         set dn "dc=testgroup,dc=com"         set type regular         set username "administrator@testgroup.com" end In capture it is observed an unbind request is observed sent from FortiGate. Downgrading to v7.4.8 resolves this issue, indicating a problem with the 7.4.9 version. The issue has been reported with a known issue ID 1228733 and is scheduled to be fixed in v7.4.10. This issue is not observed in the 7.6 version.