Careful Cast Corrector or CCC for short, is a Patch for Minecraft 1.7.x that fixes a extreme rare case of Crashing in Worldgen.
The Spawner room in Minecraft has missing checks that can cause crashes at any time they spawn.
This Mod adds this extra check that was added in later MC versions.
This mod is Highly Suggested to be used with "Chunk Pregenerator" to increase its stability.
Thanks to Chocohead for writing the ASM code.