AD Authentication enabled for domain without AD

We are currently using SD+ 5.0. I was actually testing the Import Active Directory when I encountered a problem. Here are the steps that I did:

1. Admin > Active Directory > AD Authentication Disabled > trying to import AD however message reads like "Cannot bind with the domain" maybe because I was using the wrong Domain Name.

2. I was not able to Import AD yet I tried to Enable AD Authentication. I clicked on Enable until there was no response from the program. Meaning, it hanged up. So, I decided to end the program using the Windows Task Manager. However, when I tried to login, AD Authentication is already enabled. I have an administrator account but it won't work on all domains, and I cannot even login without selecting one.