If I run this code on a new workbook it works perfect, get the error running on my workbook. Not sure
what to look for in my workbbook that causes the problem? If I highlight the text and hit the delete button everything works OK, If I just move the cursor to the box and hit delete I get the error.
Thanks for any suggestions 

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Intersect(Target, Cells(16, "C")) Is Nothing Then
        If InStr(Target, "/") > 0 Then
            MsgBox ("You Can't use that darn slash / character in the [Job Location Box] !! Use the Hyphen - Symbol")
        End If
    End If
End Sub