Why MS Excel crashes and closes during Worksheet_Change Sub procedure?

Question

I am having a problem with Excel crashing, when I run VBA code on an excel sheet.
I'm trying to add the following formula on worksheet change:

Private Sub Worksheet_Change(ByVal Target As Range)    Worksheets("testpage").Range("A1:A8").Formula = "=B1+C1" End Sub 

When this code is run i get a message saying "excel has encountered a problem and needs to close" and excel closes.

If I run the code in the Worksheet_Activate() procedure, it works fine and doesn't crash

Private Sub Worksheet_Activate()    Worksheets("testpage").Range("A1:A8").Formula = "=B1+C1" End Sub 

But I really need it to work in the Worksheet_Change() procedure.

Has anyone experienced similar crashes when using the Worksheet_Change() event and can anyone point in the right direction to fix this issue ?

Answer 1

I recommend this when using Worksheet_Change

1. You do not need the sheet name. In a Sheet Code Module, an unqualified Range reference refers to that sheet. That said, it is clearer to use the Me qualifier. If you are trying to use another sheet, then qualify the range reference with that sheet.

2. Whenever you are working with Worksheet_Change event, always switch Off events if you are writing data to any cell. This is required so that the code doesn't retrigger the Change event, and go into a possible endless loop

3. Whenever you are switching off events, use error handling to turn it back on, else if you get an error, the code will not run the next time.

Try this

Private Sub Worksheet_Change(ByVal Target As Range)     On Error GoTo Whoa          Application.EnableEvents = False          Me.Range("A1:A8").Formula = "=B1+C1"      Letscontinue:     Application.EnableEvents = True     Exit Sub Whoa:     MsgBox Err.Description     Resume Letscontinue End Sub 

Few other things that you may want to know when working with this event.

If you want to ensure that the code doesn't run when more than one cell is changed then add a small check

Private Sub Worksheet_Change(ByVal Target As Range)     '~~> For Excel 2003     If Target.Cells.Count > 1 Then Exit Sub          '     '~~> Rest of code     ' End Sub 

The CountLarge was introduced in Excel 2007 onward because Target.Cells.Count returns an Long value which can error out in Excel 2007 becuase of increased total cells count.

Private Sub Worksheet_Change(ByVal Target As Range)     '~~> For Excel 2007     If Target.Cells.CountLarge > 1 Then Exit Sub     '     '~~> Rest of code     ' End Sub 

To work with all the cells that were changed use this code

Private Sub Worksheet_Change(ByVal Target As Range)     Dim aCell As Range          For Each aCell In Target.Cells         With aCell             '~~> Do Something         End With     Next End Sub 

To detect change in a particular cell, use Intersect. For example, if a change happens in Cell A1, then the below code will fire

Private Sub Worksheet_Change(ByVal Target As Range)     If Not Intersect(Target, Me.Range("A1")) Is Nothing Then         MsgBox "Cell A1 was changed"         '~~> Your code here     End If End Sub 

To detect change in a particular set of range, use Intersect again. For example, if a change happens in range A1:A10, then the below code will fire

Private Sub Worksheet_Change(ByVal Target As Range)     If Not Intersect(Target, Me.Range("A1:A10")) Is Nothing Then         MsgBox "one or more Cells in A1:A10 range was changed"         '~~> Your code here     End If End Sub