The Fire Pit

Hello
Using Windows 10 and the game is giving AI inactive error message in the pit area. Creature does not move and after turning on the fire jet to destroy the creature i go down the pit and can go no further. Door at bottom will not Open.
So i assume we cannot finish the game
Running software on Windows 10 Pro version 10586.36 AMD motherboard with 6 core AMD cpu and R7 graphics card with latest drivers
7 hours worth of play for 15 Quid sterling

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valveā€™s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.