VMware vSphere ESXi 7.0.x
VMware vSphere ESXi 8.0.x
An incorrect value was entered in the Security.PasswordQualityControl field under the ESXi Advance System Settings. This value changed when hardening the password parameters on the ESXi hosts. See vSphere Security
To resolve the issue, remove the incorrect entry from Security.PasswordQualityControl field
Reference Articles: vSphere Single Host Management - VMware Host Client