Portal:Env Fire fix
The Env_fire entity is broken in portal. There's actually a fixable reason as to why this is.
In the Source engine, the Env_fire entity looks for the particle "fire_01.pcf" to use. This contains all the necessary particles, like smoke, large/medium/small fires, etc. In Half Life 2, this works fine.
However, in Portal, the fire pit particles seen at the end of the test chambers are also named "fire_01.pcf". This creates some conflicts, as the Env_fire can't find the correct particles within the Portal fire pit particle system. This is further complicated by the absence of any Env_fires in the original Portal. Had any been placed during development, this problem would have been dealt with far before Portal was released.
This fix tells Portal that the env_fire entity can use fire_02.pcf (the renamed fire_01.pcf from Half-Life 2). If you distribute a map with an env_fire in it, you MUST include this fix! Otherwise your map will be broken!
There are a few issues with the fix, however. First, some have reported that the fire is mute (no sound). Second, the "Fire Size" keyvalue has no effect on the ingame fire; it remains the same size no matter what value the entry has (thanks to reepblue for pointing that one out).
Link to Fix
The link to the fix is broken as of now.
Env_fire fix by NocturnalGhost, packaged by WinstonSmith