[1.7] Stone Age Texture Pack crashes when spawning a skeleton

Verification builds:

Ver. 1.7.2, Build 1117901

Summary:

The Stone Age Texture Pack causes the game to crash whenever a skeleton exists in the world. This doesn't happen with Alien Worlds Texture Pack or default textures.

Impact:

Game crashes whenever a skeleton exists.

Repro Steps:

1. Download Stone Age Texture Pack
2. Create a world with Alien World Texture Pack and mob spawning set to false!
3. Summon a skeleton

Observed Results:

The game crashes with the following assert:

Assertion failed: This should be empty by this point, if it's not we've got a problem!
Condition is false: mEntities.empty()
Function: MultiPlayerLevel::~MultiPlayerLevel in f:\darwinwork\18\s\handheld\src-client\common\client\multiplayer\multiplayerlevel.cpp @ 28

Expected Results:

Game shouldn't crash

Screenshots/Videos attached: 

No, only assert message. 

Regression Build

1.6.0.8

Notes:

Doesn't seem to happen with other texture packs?