Try the latest download from here. If it still gives you problems, let me know, and I'll get you a debug build
Latest Beta build for Act III is here:
https://mega.nz/#!OupwRKwb!PD7yVx2GIUdThufWfF3tzj4youu_BT9PZsLL8BLdQuw
If that's not working, could you get me the savegame folder, and I'll see what's happening.
Also: I played your savegame, and progressed to the next dialog: could you see if that works?
https://mega.nz/#!n6xDVZpK!nF0eiMN2sMqbc_e9isFh5NWtI7Ti4HOZx5Gdiadg3zU