External Content type failed to save, The name domain\username cannot be resolved via Active Directory

Hi All,

I get the below error when I was trying to edit the external content type through SharePoint Designer. The Name Domail\username, is no longer with our organization. I believe he created this External Content Type, and I can't save it after making some changes. I am trying to edit with the farm account. Can anyone please provide instructions on how I can resolve the issue? Any help would be really appreciated. Thanks in advance.

Thanks,

Cherry