Help - Cancel MsgBox If Condition is Met

Hello ACPNR ,

I think all you need to do is add another condition to the IF statement so it says in words "If the Code is X and the cell next to it is blank" then show the message.

You only need to loop through the codes in column H,  and you don't need the $ signs in the range reference.  Also, when you dim several elements in one row of code, you need to specify the data type of each. If you don't, it will be a variant. 

Also, you don't want to loop through the whole list. You only want to check the row where the data was entered, i.e. the target cell in column H. Therefore, the code should only watch column H, not column I.  When you operate on the target cell, you don't need to declare any ranges at all. 

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Intersect(Target, Range("H15:H32")) Is Nothing Then
        If Target.Value = "X" And Len(Target.Offset(0, 1)) = 0 Then
                MsgBox ("Please include a repair comment for corresponding line.")
        End If
    End If

End Sub

If you want to cater for a scenario where several rows of values are filled in at once, for example with a copy / paste operation, THEN you would need to loop through all the cells in the target. In that case it would also help to give the user an indication which row needs to be addressed.

Private Sub Worksheet_Change(ByVal Target As Range)
Dim cel As Range
    If Not Intersect(Target, Range("H15:H32")) Is Nothing Then
        For Each cel In Target
            If cel.Value = "X" And Len(cel.Offset(0, 1)) = 0 Then
                    MsgBox ("Please include a repair comment for row " & cel.Row & ".")
            End If
        Next cel
    End If

End Sub