Stàr

You didn't download and use my pack then? Because that shouldn't happen if you do. The only thing that should be in the Extras menu is "Unlock previous chapters". As for the Start game menu - there will always be at least three options there (arcs), but two of them will be locked. This is what the main menu looks like with nothing unlocked or completed: http://i.imgur.com/ZBBDMxP.jpg

Well if you just want to use some other version you downloaded and want to remove the unlocks it has, then delete the "BGI.gdb" file in the game folder. That will reset all options and unlocks. Make sure you put "Function of right click" to Call Menu in the options menu afterwards.

Also make sure you've got the latest PC music + sound patch for the game if you're not actually using my pack.

The scenario jump mode is something that you gain access to for a specific arc after finishing said arc. It only pops up when you start the arc. With it, you can jump to any day/event of that arc.