Excel VBA "Method Range of object _worksheet failed - vba

Question

I am trying to do some VBA programming but running into a strange situation. The code below runs fine in one excel file but not another, the error in the title appears in the line where I assign SearchRange variable.
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$B$3" Then
Dim rngX As Range
Dim counter As Integer
Dim wsLeit As Excel.Worksheet
Dim wsFilt As Excel.Worksheet
Dim searchValue As String
Dim searchRange As Range
Dim rownr As String
Set wsLeit = Excel.ThisWorkbook.Sheets("Leit")
Set wsFilt = Excel.ThisWorkbook.Sheets("FILT")
Set searchRange = wsFilt.Range("A4:ZZ10000")
searchValue = wsLeit.Range("B3").Value
Set rngX = searchRange.Find(what:=searchValue, lookat:=xlPart)
wsLeit.Range("A6:B200").ClearContents
If Not rngX Is Nothing Then
strFirstAddress = rngX.Address
counter = 8
rownr = Split(rngX.Address, "$")(2)
For Each c In wsFilt.Range("A" & rownr & ":" & "ZZ" & rownr)
If Not IsEmpty(c.Value) Then
wsLeit.Range("A" & CStr(counter)).Value = c.Value
foundColumn = Split(c.Address, "$")(1)
wsLeit.Range("B" & CStr(counter)).Value = wsFilt.Range(foundColumn & "1").Value & " " & wsFilt.Range(foundColumn & "2").Value
counter = counter + 1
End If
Next
Else
MsgBox "Fann ekkert"
End If
End If
End Sub
Any idea why this code works in one workbook but not another? (the sheets have the same name in both books)
EDIT1:
For completeness sake here is the full error:
Runtime Error '1004':
Method 'Range' of object '_Worksheet' failed

Answer 1

The problem was that pre-Excel 2007 versions have a smaller number of columns, and this sometimes creates random failures when the file format changes.
Some Excel 2003 specs:
Worksheet size 65,536 rows by 256 columns
Column width 255 characters
Row height 409 points
Page breaks 1000 horizontal and vertical
Excel 2010:
Worksheet size 1,048,576 rows by 16,384 columns
Column width 255 characters
Row height 409 points
Page breaks 1,026 horizontal and vertical
Total number of characters that a cell can contain 32,767 characters
A good practice to safeguard against this problem is to add a "guard" subroutine in the Workbook_Open event that checks (using Application.Version) if the current excel version is the minimum one for which the file is meant to be. You can store the minimum excel version in the Workbook.Names Collection as a constant and check against that constant.
I hope this helps!