I'm running a vCenter Server 6.5. There's no problem logging into vCenter SSO with the default administrator-user. However, I've tried adding a new user but I'm simply not allowed to login with it, I've added it to all the administrator-groups in vCenter too for the sake of testing. It's in the same local domain as the administrator "@vsphere.local" (which I'm using to login as well) and for simplicity I've even given them the same password. It's joined to AD or such, local users. But all I get is "Invalid credentials" when I try to use it when I try to loggining with newly added users..
I see this community Invalid credentials for newly added user but url http://www.virtuallypeculiar.com/2016/11/vsphere-65-login-to-web-client-fails.html does not open.