Program: 39448
Project: 39448
Buggy source:
public static void preInit(){
  CHAMELEON_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityChameleon.class,0.25F){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return BiomeDictionary.hasType(biome,BiomeDictionary.Type.PLAINS) && super.isBiomeSuitable(biome);
    }
  }
);
  FILCHLIZARD_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityFilchLizard.class,0.25F){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return BiomeDictionary.hasType(biome,BiomeDictionary.Type.SANDY) && super.isBiomeSuitable(biome);
    }
  }
);
  GROVESPRITE_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityGroveSprite.class,0.25F){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return BiomeDictionary.hasType(biome,BiomeDictionary.Type.FOREST) && super.isBiomeSuitable(biome);
    }
  }
);
  BRAINSLIME_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityBrainSlime.class,0.5F){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return (BiomeDictionary.hasType(biome,BiomeDictionary.Type.BEACH) || BiomeDictionary.hasType(biome,BiomeDictionary.Type.RIVER)) && super.isBiomeSuitable(biome);
    }
  }
);
  HAUNTEDTOOL_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityHauntedTool.class,0.15F),new Type[]{Type.BEACH});
  ROCKETCREEPER_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityRocketCreeper.class,0.25F));
  FESTIVECREEPER_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityFestiveCreeper.class,0.15F));
  SUPPORTCREEPER_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntitySupportCreeper.class,0.15F));
  TREASURESLIME_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityTreasureSlime.class,0.2F));
  BEWITCHEDTOME_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityEnchantedBook.class,0.3F));
  SKELETONWARRIOR_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntitySkeletonWarrior.class,0.25F));
  LILYLURKER_SPAWNS=registerSpawnWater(new PrimitiveMobsSpawnEntry(EntityLilyLurker.class,0.3F){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return (BiomeDictionary.hasType(biome,BiomeDictionary.Type.SWAMP)) && super.isBiomeSuitable(biome);
    }
  }
);
  BLAZINGJUGGERNAUT_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityBlazingJuggernaut.class,0.25F){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return (BiomeDictionary.hasType(biome,BiomeDictionary.Type.NETHER)) && !BiomeDictionary.hasType(biome,BiomeDictionary.Type.END);
    }
  }
);
}

Fixed version (ground truth):
public static void preInit(){
  CHAMELEON_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityChameleon.class,PrimitiveMobsConfigSpawns.chameleonSpawnRate){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return BiomeDictionary.hasType(biome,BiomeDictionary.Type.PLAINS) && super.isBiomeSuitable(biome);
    }
  }
);
  FILCHLIZARD_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityFilchLizard.class,PrimitiveMobsConfigSpawns.filchLizardSpawnRate){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return BiomeDictionary.hasType(biome,BiomeDictionary.Type.SANDY) && super.isBiomeSuitable(biome);
    }
  }
);
  GROVESPRITE_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityGroveSprite.class,PrimitiveMobsConfigSpawns.groveSpriteSpawnRate){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return BiomeDictionary.hasType(biome,BiomeDictionary.Type.FOREST) && super.isBiomeSuitable(biome);
    }
  }
);
  BRAINSLIME_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityBrainSlime.class,PrimitiveMobsConfigSpawns.brainSlimeSpawnRate){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return (BiomeDictionary.hasType(biome,BiomeDictionary.Type.BEACH) || BiomeDictionary.hasType(biome,BiomeDictionary.Type.RIVER)) && super.isBiomeSuitable(biome);
    }
  }
);
  HAUNTEDTOOL_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityHauntedTool.class,PrimitiveMobsConfigSpawns.hauntedToolSpawnRate),new Type[]{Type.BEACH});
  ROCKETCREEPER_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityRocketCreeper.class,PrimitiveMobsConfigSpawns.rocketCreeperSpawnRate));
  FESTIVECREEPER_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityFestiveCreeper.class,PrimitiveMobsConfigSpawns.festiveCreeperSpawnRate));
  SUPPORTCREEPER_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntitySupportCreeper.class,PrimitiveMobsConfigSpawns.supportCreeperSpawnRate));
  TREASURESLIME_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityTreasureSlime.class,PrimitiveMobsConfigSpawns.treasureslimeSpawnRate));
  BEWITCHEDTOME_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityEnchantedBook.class,PrimitiveMobsConfigSpawns.bewitchedTomeSpawnRate));
  SKELETONWARRIOR_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntitySkeletonWarrior.class,PrimitiveMobsConfigSpawns.skeletonWarriorSpawnRate));
  LILYLURKER_SPAWNS=registerSpawnWater(new PrimitiveMobsSpawnEntry(EntityLilyLurker.class,PrimitiveMobsConfigSpawns.lilyLurkerSpawnRate){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return (BiomeDictionary.hasType(biome,BiomeDictionary.Type.SWAMP)) && super.isBiomeSuitable(biome);
    }
  }
);
  BLAZINGJUGGERNAUT_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityBlazingJuggernaut.class,PrimitiveMobsConfigSpawns.blazingJuggernautSpawnRate){
    @Override public boolean isBiomeSuitable(    Biome biome){
      return (BiomeDictionary.hasType(biome,BiomeDictionary.Type.NETHER)) && !BiomeDictionary.hasType(biome,BiomeDictionary.Type.END);
    }
  }
);
  SPIDERFAMILY_SPAWNS=registerSpawnNormal(new PrimitiveMobsSpawnEntry(EntityMotherSpider.class,PrimitiveMobsConfigSpawns.spiderFamilySpawnRate));
}