How to make changes in a new workbook opened from an active workbook

Iam using the following code to save a range in the active workbook into a new workbook.

Sub OutputN(SheetName As String, n, FilePath, SaveName As String, FileType)
  
    ThisWorkbook.Sheets(SheetName).Activate
   
   ' On Error Resume Next
        ThisWorkbook.Sheets(SheetName).Range(SheetName & "_Summary" & n).Copy
       'Application.DisplayAlerts = False
        Workbooks.Add
        Selection.PasteSpecial Paste:=xlPasteValues
        If FileType = xlOpenXMLWorkbook Then
              EditSheet SheetName
        End If
        
                 
                        ActiveWorkbook.SaveAs Filename:=FilePath & SaveName, _
                        FileFormat:=FileType, CreateBackup:=False
                 
    ActiveWindow.Close
    ThisWorkbook.Sheets(SheetName).Activate
    Application.DisplayAlerts = True
    
End Sub

This works fine as long as the line EditSheet SheetName is excluded. If it is used then I get a message "subscript out of range" because of course there is no sheet called sheetname in the new workbook.
I am sure there must be a simple way out of this out of this corner, but I can't find it.
Can anyone help please.
John