1. Start the game
2. Go to menu -> options
3. change Texture detail to lower than maximum.
4. Join a server (Lan or Internet)
5. Game will now be frozen
-or-
1. start the game
2. join a server (lan or internet)
3. press ESC and select options
4. in graphics tab , change the texture detail to lower than max.
5. The game freezes.