Worksheet_Change(ByVal Target as Range) doesn't work - excel

Question

Probably I'm missing something but the most simple "Worksheet_Change" doesn't work at all. The code is placed in the correct worksheet and is exactly the same as in samples I have found in my search to solve the problem. Please ignore the lines that start with "'" as they will be part of the code after the issue is solved. I've simplified the code in trying to localize the issue but as I said, even this simple code doesn't work, even if I use a new Workbook with only one sheet. As said, I might be missing something completely simple but for the moment, I don't know what it is. Thank you.
Jan
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
' Dim KeyCells As Range
' Set KeyCells = Range("Orders[Nieuw]")
' If Not Application.Intersect(Range("Orders[Nieuw]"), Target) _
' Is Nothing Then
' If Target.Address = "$C$10" Then
Application.EnableEvents = False
' If Target.Value = "Ja" Then
MsgBox "This Code Runs When Cell A1 Changes!"
Target.Font.ColorIndex = 5
' Range("AG2").Select
' Selection.Copy
' Range("Ordernummerbereik").Select
' Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
' :=False, Transpose:=False
' SendKeys ("{ESC}")
' End If
Application.EnableEvents = True
' End If
End Sub

Answer 1

You probably ended up in EnableEvents = False and therefore no events will be executed anymore including the Worksheet_Change event.
When using Application.EnableEvents = False make sure you use proper error handling that returns it to True otherwise if an error occurs it stays False until you close Excel.
Example for error handling
Public Sub Example()
Application.EnableEvents = False
On Error Goto EventsOn
' your code here
EventsOn:
Application.EnableEvents = True
If Err.Number Then Err.Raise Err.Number ' show the error message
End Sub
That means if any error occurs in your code it jumps to EventsOn: turns events on and throws the error message. This way you ensure that Events are always turned on in case of an error.

Answer 2

The only way I can reproduce your problem is by setting EnableEvents to false outside of the sub. Perhaps it crashed at some stage leaving events disabled?
Incidentally you can replace the copy and paste with
Range("Ordernummerbereik").Value = Range("AG2").Value
which is much more robust
Finally I advise you to use fully qualified ranges for ranges without an explicit name e.g. ThisWorkBook.Sheets("Sheet1").Range("A1") rather than Range("A1")
You can use (note the dot-Range on AG2)
With ThisWorkBook.Sheets("Sheet1")
Range("Ordernummerbereik").Value = .Range("AG2").Value
' ... other code with range references
End With