I think you get this message when the game is in multiplayer mode, maybe check your launch parameters or config to make sure you're not changing mode. If you start the map using map <mapname>
and no other parameters then it should be in singleplayer by default (deathmatch 0
).
This of course applies to standard HL, if you're trying to make a singleplayer mod for a multiplayer game (like cstrike
) then you will have trouble.