Fixing an error where "Thisworkbook" is duplicated

So there is an error that I have seen a few times where the "thisworkbook" object gets duplicated. (so if you go into the vba editor you will see two thisworkbook modules or maybe one thisworkbook and a thisworkbook1 module, maybe other modules will also be duplicated)
This will cause the sheet to probably crash. After some effort a retrieved copy of the file will probably be able to be opened.

I have found that the solution seems to be to just copy all the worksheets over to a new template workbook. So assuming I have a template with all the correct vba in it (as i will have) I want to write some fairly generic code to repair the file.

So this (embarrassingly badly written) code below might be of use to quite a few people given the messages I have seen online about this (you run it when the file is open and it will ask you to browse to a template then it will move the sheets to that template)

However I still have a couple of issues my problem is that
1) just moving the sheets seems to ruin my named ranges (is there anything else it might ruin? I want this as robust as possible)
2) in practice the file will crash when I open it meaning there is quite an annoying process to get it to open, which is the essential first step in the process. I'd like to be able to run this process without having to properly open the file if possible. (maybe there is a better methodology)

Sub Rebuildsheet()
Dim wb1 As String, wb2n As String, wb2 As Workbook
Dim mySaver As FileDialog
Dim sh As Worksheet
    With ActiveWorkbook
        .Sheets.Add(After:=.Sheets(.Sheets.Count)).Name = "MyTemp"
    End With 
Application.ScreenUpdating = False
wb1 = ActiveWorkbook.Name
   Application.DisplayAlerts = False
   wb2n = Application.GetOpenFilename("Select Template Excel Files.  (*.xls*),*.xls*")
Workbooks.Open Filename:=wb2n
Set wb2 = ActiveWorkbook

On Error Resume Next
For Each sh In Workbooks(wb1).Worksheets
 If sh.Name <> "MyTemp" Then

                wb2.Activate
                wb2.Sheets(sh.Name).Delete
         Workbooks(wb1).Sheets(sh.Name).Move After:=wb2.Sheets(wb2.Sheets.Count)
         Else: End If
    Next
Workbooks(wb1).Close

    MsgBox "Finished - please save file in appropriate location"
'    ActiveWorkbook.SaveAs Filename:=Workbooks(wb1).path & "\repaired.xlsm"

Set mySaver = Application.FileDialog(msoFileDialogSaveAs)
With mySaver
    .Title = "Save this repair as..."
    .InitialFileName = "repaired.xlsm"
    .Show
    ActiveWorkbook.SaveAs Filename:=.SelectedItems(1), _
       FileFormat:=xlOpenXMLWorkbookMacroEnabled
End With
    Application.DisplayAlerts = True
    Application.ScreenUpdating = True
End Sub