View Changes dialog box opening with top level machines

hello

who can tell me why, when I open, on an empty workspace, my top level machine, I have this View Changes dialog box opening

this is not happening for any other assembly


ptc help says:
About the View Changes User Interface
When you retrieve an assembly modified in Creo Direct or view changes to an assembly or assembly component the View Changes dialog box opens with the following user interface items:

but I dont use Creo Direct and I don 't request this information windows

thanks

Veronique