Can't Reset User's Password in SEI

SOLVED

Received a request from a user that he could no longer access his account nor reset his password. Upon attempting to reset the password myself, I received the error message below: "Cannot reset password for an active directory user"

I believe the root cause to be that his account is linked to a Domain, as shown below. Other accounts do not have this error message appear and are also not linked to any Domain. 

How can I reset this account?