Going back to post #8 -
This line is incorrect: If IsNull(Me.ReceivedBy) Then Me.txtReceivedBy = [Forms]![LoginForm]![cboUser].[Column](1)
"Column" cannot be in square brackets - it is a property, not a field or control name, and properties can't be in square brackets.
It should be: If IsNull(Me.ReceivedBy) Then Me.txtReceivedBy = [Forms]![LoginForm]![cboUser].Column(1)