Well, this is NOT the usual question about what means and which tactics to use defeating Kangaxx in both his forms. I've read quite a few about them and did everything after the book: Five out of six characters wielding +4 o +5 weapons, tons of summons including nishruus and Mordie's swords, true sight and the whole dispel-o-rama.

The plan went flawlessly. I laughed at the pitiful resistance of his lich form and when he belived he turned the tables with his demi-lich form I quickly shattered his illusion and saw with satisfaction as i saw the dust from his shattered skull and his wonderful ring drop to the ground.

Then something weird happens: The statusbar and the cursor dissapears as though I was going to watch a cutscene but nothing happens. A remaining efreeti that Kangaxx had summoned proceed to attack Jan while I can do nothing but watch.

A crude Alt F4 is the only remaining option. What exactly went wrong?? Did Kangaxx imprison my computer as a last defense?

Did you accidentally press H, cuz that would make the statusbar disappear.

Nope. Besides "H" doesn't make the cursor dissapear too.

Now that, is a bug I have never heard of before! Look around for patches!

I have installed the Bioware patch.