Does anyone know where and how to start this ??                                                                             

You need to go back to the Rebel Coordinator and get a new WP for Leiah.  The same thing happened to me except i just asked for the same WP again instead of getting a new one. It kept sending me back to an empty location. I can't remember exactly which prompt to select, but you should be able to figure it out. That should fix it for ya.            

Whether this is the final or not I do not know.

After having the encoded disk decoded. You are told Leiah wants to meet you. (even if you have finnished the rebel themepark and met her already, lol)

Once you arrive at her WP she tells you of attacks being staged against the rebel flora factories and askes you to help defend them.

I was given a wp, defended it against 15 ST's
then a second wp with 20 ST's
and a third with 25 ST's that I was unable to defend because I brought no help, and the Rebel NPC's are worthless. Then my WP's stopped appearing, so I have no clue how to proceed... HELP!!!