Steam’s default folder has stricter permissions and different registry keys. Follow this alternative:

You cannot simply drop files into a random folder. Follow these prerequisites strictly.

Many old links (from 2010-2015) are dead. As of 2026, here are the verified safe sources for Los Angeles Mod v3.15:

Emergency 4: Los Angeles is a city-building and emergency management simulation game. It's part of the Emergency series, which focuses on disaster management and response.