Unable to Create User Account in AD

Hello, 

I am trying to create a new user in AD (Windows Server 2012 R2) When I attempt to create a new user I receive an error:  "the specified domain either does not exist or could not be contacted" 

I'm also receiving an error if I open up an existing user object: "the pre-windows 2000 domain name for the user object cannot be displayed". 

I cannot recall changing settings on our AD Server.