Hello, I need help as I am really getting annoyed at this bug. I cannot mount any of the steam source mods. I can mount the main games (CS:S, HL2, EP2, L4D) but I cant mount any of the source mods (PVKII, AOC, ZPS). I also can’t mount Half-Life: Source, Deathmatch: Source or Zeno Clash. Any reason for this?
The issue is that those games have not updated to Valve’s new content system, Steampipe. If you want the content from them, you’ll have to manually extract them using GCFScape. Half-Life: Source has also not been updated for whatever reason. To get Zeno Clash to work, install the Zeno Clash Models in the Tools section.
Also, you would have to have Gm_Mount 2, which is currently broken and has not been updated for while
He’s talking about officially supported games, not non-steam sourcemods.