I had the following code in a VBA which, when I opened the Workbook showed
Error '13' - Type mismatch, I believe relating to the Set c =
Range("M7:M20") line. I exited the error and it would function ok.

Private Sub Worksheet_Calculate()
Set c = Range("M7:M20")
For Each i In c
If i.Value = "Yes" Then
i.Value = i.Value
End If
Next
End Sub

But now, the line in the code has changed itself back to

Set c = Range("M7")

which was the range we had in an earlier code, and obviously only works on
cell M7. I can change the "M7" to "M8" etc, but as soon as I try to change
the range back to ("M7:M20") as I need it, Excel and the VBA freeze.
Does anyone know how I may overcome this?
--
Cheers
cliff18