I did some investigating and I changed the access db in two places

 

1. in table: CuteChat4_SuupportAgent

      Changed DepartmentID  - took off Primary Key and allowed duplicates.

That only makes sense for this column has duplicates.

 

2. In Table: SampleUsers

      Change Email field to be NOT required.  Since you do not have that field in the Manage Operators page, adding the first operator works fine, but when adding a second it errors out because it is trying to insert a "blank" email which is a duplicate and not accepted.