Modified by me.
I played this map in Missing Information 1.5 mod and when i complided the hazard01 without any fixes it worked almost perfectly in MI.
Because the map was made in 2002, it had some HL1 entities like multi_manager wich doesnt exist in HL2 hammer anymore so i had to make minor fixes to get all work.
I have HL2 Beta hammer but cant get it to work for some reason.