Run-Time Error 2023

Evening All

I've been using the below code to change the data range within the workbook for ages and now all of a sudden it's not working:

All I do is increase the range by one column every week

Sub ChangeAllCharts()
Dim sht As Worksheet
Dim cht As ChartObject
Dim ser As Series

For Each sht In ActiveWorkbook.Worksheets
For Each cht In sht.ChartObjects
For Each ser In cht.Chart.SeriesCollection
ser.Formula = Replace(ser.Formula, ":$CY$", ":$CZ$")
Next ser
Next cht
Next sht
End Sub

Thanks for any help.
Stewart

Sorry forgot to show debug

Any ideas anyone ???

Fixed it :)

Cold you tell us how you fixed it?? I made an account just to ask this ahah