Many thanks Jessen

It seems to work with a small amount of tweaking. This is what I've
finished with:


Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As
Range)


Cells.ClearComments
Dim TempCell As Range
Dim rc As Integer
Dim NoShow As Boolean


For Each TempCell In ActiveSheet.UsedRange
If Not TempCell.Validation.Value Then
If NoShow = False Then
rc = MsgBox("Please ensure the circled data is entered correctly "
& vbLf & "(including formatting) and paste as values only", 16, "Data
Validation Error ")
End If
NoShow = True

ActiveSheet.CircleInvalid

End If
Next
End Sub