After the first dialog scene with Morte, I am having a bunch a problems. I cannot select the Nameless One, and there is random gibberish being said by Morte, like the audio is broken. I am also not able to select the table to acquire the knife and continue the game.

Did you apply this fix and mod before playing:
http://www.gog.com/en/news/mod_spotlight_planescape_torment_mods_guide/

it's necessary because this game has plenty of bug from the get-go.

Yup, applied all the mods.

I tried the game again and it seems to be working for now. Thanks

Ok, The problem is back. Is there anyone who knows how to fix this?