When the Orange Box came out, it broke many mods, SMOD being one of them. I believe this version should work with the current HL2 version distributed by Steam:

When the Orange Box came out, it broke many mods, SMOD being one of them. I believe this version should work with the current HL2 version distributed by Steam: https://www.moddb.com/mods/smod/downloads/smod-40a-piped https://www.moddb.com/mods/smod/downloads/smod-40a-piped