[shanapu]

Would you please tell us which entity you used for l4d2? So I can do an engine check and add both particles.
But it's still weird, in the wiki you can read about new functions for the "env_steam" introduced with L4d2.
https://developer.valvesoftware.com/..._L4D2_Entities
https://developer.valvesoftware.com/wiki/Env_steam

Am I missing something?