Attempting to operate the Source SDK Hammer Level Editor in the Source 2006 engine for Half-Life 2 Deathmatch currently results in an error of: "Missing material, ...verify that your game directory is correct." If you have this problem, read on! This is a Source SDK bug caused by Valve and this is a work-around to fix the issue and operate the game in the Source 2009 version of the engine.

The cylinder method!

Create and view sprites

Zoner's Half-Life Tools - Custom Build 1.7 by Merl

A ceiling light, comes without a lightbulb