Another 1004 error problem

I have an xlt file which when opened has a button to click to save the file as an xls in a specific sub-folder. I did have this code working but have been away for a month and on my return it seems to have developed the 1004 error.
In the following code all the Ranges exist in the workbook and the worksheet is named Operation. The code fails at the line starting ActiveWorkbook

Private Sub SaveFile_Click()
'
' SaveFile Macro
'
Dim Dt As Date
Dim Ex As String

Dt = Range("StartDate").Value
Ex = Left(ExIncOp, 2)
'
        If IsEmpty(Worksheets("Operation").Range("ExIncOp")) Then
    Msg = MsgBox("Please enter TYPE in cell C6 to continue ", vbOKOnly)
        End If
        
        If IsEmpty(Worksheets("Operation").Range("Name")) Then
    Msg = MsgBox("Please enter NAME in cell H6 to continue ", vbOKOnly)
        End If
    
        If IsEmpty(Worksheets("Operation").Range("StartDate")) Then
    Msg = MsgBox("Please enter DATE FROM in cell E10 to continue", vbOKOnly)
        
Exit Sub
        End If

    ActiveWorkbook.SaveAs Filename:=ThisWorkbook.Path & "\" & Range(Debrief_Folder) & Range("Ex").Value _
    & " " & Range("Name").Value & " " & Format(Dt, "dd-mmm-yy") & ".xls", FileFormat:=xlNormal

End Sub

The file should save into \"Debrief_Folder"+"1st 2 letters of variable Ex"+"Range Name"+"date in format 28-Feb-08"+".xls"

Can anyone see what the problem is?

I thought I had sorted this with previous help from this group

Antonio,

Thanks for your reply, and yes Debrief_Folder should have been "Debrief_Folder", but it still doesn't work

Regards

Further to my last I believe that .Value should be inserted after "Debrief_Folder") as follows, but it still doesn't work!

    ActiveWorkbook.SaveAs Filename:=ThisWorkbook.Path & "\" & Range("Debrief_Folder").Value & Range("Ex").Value & " " & Range("Name").Value & " " & Format(Dt, "dd-mmm-yy") & ".xls", FileFormat:=xlNormal

Regards

I have now discovered that the problem in the code is

Range("Ex").Value

as

     ActiveWorkbook.SaveAs Filename:=ThisWorkbook.Path & "\" & Range _
     ("Debrief_Folder").Value & "\" & Range("Name").Value & " " & Format _
     (Dt, "dd-mm-yy") & ".xls", FileFormat:=xlNormal

works as it is meant to.

So why does the first bit of code not work?

Ex = Left(ExIncOp, 2)

defines Ex as a String and as the first 2 letters of whatever is in the range ExIncOp. Does this mean Ex is not a Range? as it is defined within the code?