I had this problem as well. Does the dark jedi pop up in the middle of the room? Did Revan fade away, or did he stay for a while then pop out of existence? Are you able to get into the crypt? Is your mouse not working?
This has happened before. If you have a previous save point in the tomb, then use it. you shuld make one in between wach of the events. Its probably the best thing to do.
This is a bug that pops up frequently. I know that its been discussed here. We found that you had to start over. Although there were many possible solutions, that is the only one that worked. Sorry for the inconvienience.
You will know that you can escape when you hear Kreia after you defeat Revan, or, sometimes, another bug, after you open the tomb door. If this is not happening, try all the doors. That is a sign that you need to restart.
This game is somewhat buggy. Since I havent seen you post before, you must be a lucky one. My first time through I had to end the game early because on Telos, the door closed to the exchange office before I could get it. A truly frusterating experience.
Doesnt look like youll have any more problems. Most of the bugs appear on the same planets...for me, Korriban in peticular, had the worst one. You should probably quicksave every 15 minutes or so, by pressing F4, I think. Always works. you never know when the next bug pops up...
And, since this bug and another seem to go hand in hand, Ill warn you about another. sometimes in the game, you will come to the invisible door. This is when you try to go through an open door and cant get through. Just back up, and try again. Dont try to force your way through, that does not work. Also, do not run and then hit the pause screen, or, more usually, the save screen. Your charcter will run into the nearest object, no matter how far away, when you resume gameplay. Once or twice, it was incredibly annoying, although easily predictable and I was able to get through situations fine, so its more of a hinderance.
If you geta ny other questions, dont hesitate to ask. Weve all been through the bugs, which usually ends in either reintall or go back a save point, or in game advice in general.