My Trisquel main menu have dissapeared

I'm a GNOME Flashback user (I mean the default GNOME environment of Trisquel 7)

My main menu have totally dissapeared. I only have the Trisquel applet by now.

I wanted to edit with Alacarte my application menu. But Trisquel 7 doesn't allow me as Trisque 6 did, to clic and drag some of the applications to put in personal folders inside the application menu.

I have tried to do it with Menu Libre, but it was difficult for me because I had to know the commands to create my menu and a help of Alacarte was needed to know them.

I remember it was a manipulation with Totem that mess it up.

I think there is a conflict with files made with Alacarte and Menu Libre.

Is there any way to recover the default settings ?
I can't do it with Alacarte even if a button can allow me to do it. Nothing happens.

Thank you