OK,
Firstly thanks all you guys for your help.
To answer Masillas question, I got the proton core by manipulating the console next to the missile Bay in that room.
It then gave me an option of "Taking the core" or Stepping away. I took the core.
My Journal updated and said that I had the last core and all I had to do was place it.
Thats where I got stuck and it wouldnt let me.
In any event, I had to start again from a saved game after beating Atris. When I did that - I carefully did all the charges on the ravager first before going into Visas Room, and then facing Nihilus this time.
That seemed to work.
I have seen though that other people have had this problem. So if you have, try that. Start the whole Ravager mission from the beginning. Perhaps it depends on which order you place the carges ? I have no idea and can only put it down as a bug! One of the many many.
BTW - the ending sucked - anyone else think that ? I mean all that happened for me (Spoiler alert!) is that I killed Kreia and then her 3 Lightsabres, and asked her about the future. Then it showed me a VERY SMALL movie of the ebon hawk flying away. HOW ? HOW was it repaired by whom ?
What happened to Bao Durs robot that was being confronted by Goto ?
The ending sucked man and Im still eager for more !
What a sucker eh ?
Thanks again all you people of this forum!
Dan