Anisay is right, her solution works absolutely, you must not break up the quest from Sassan all the way through to killing Laiken
That makes no bloody difference. I had completed all sidequests possible prior to meeting Sassan and heading for the tower and got the bug. The reason why you people have found the way around it is beacuse you just reached the point of the cutscene earlier after reloading an earlier save. For some people it was a close call I guess. It doesn't matter if you take a break from Sassan before the cutscene or not if all your save files are longer than the breaking point for the bug. I never took a break from Sassan. After restarting the game from the beginning I simply went past this point of the game by reaching it SOONER. But I did everything in the same order. Just a lot quicker.