Ossus mission - Descration, Speak to Master Gnost-Dura bug?

First post. I can't see that this has been posted before.

I've been subscribing/playing for 3 years and first real irritating bug. In 5.10a first Ossus mission - Descration, Speak to Master Gnost-Dural:

After defeating him he mutters 2 or 3 words then all freezes and I cannot progress any further at all. Reset/abandon then repeat does nothing and the only option is to reboot and hope it gets fixed. Very frustrating.

I'm playing as Sith Inquisitor, windows 7, 64 bit. Otherwise it is all fine; just not this mission and I can't progress the story at all. I reported the bug in game twice...

Any suggestions most welcome! Thanks ( :