Question, why did Private Sub Workbook_Open()
not work?

I have used it many times before and it worked fine.

But on this project it would not work, but if I put in an
Sub Auto_Open () routine it works fine.

---- this does not work in the ThisWorkbook

Private Sub Workbook_Open()
MsgBox "Application Opened ThisWorkbook" ' put in to debug
Display_UnitInfo
End Sub

----- But this does work on Module1

Sub Auto_Open()
Display_UnitInfo
MsgBox "Application Opened ThisWorkbook" ' put in to debug
End Sub

I can live with it, but curious why as to the Workbook_Open()
stopped working in this project.