i spawned several mobs in lava, and as they died (i think it was on their death. they explode if they die in fire/lava. it could be from spawning them too), the game crashed. it happened in other cases too though, such as event replacing entity on spawn before i disabled that.

 

https://dl.dropboxusercontent.com/u/62600417/fml-client-latest_201412130310.log

 

note, this doesn't happen in java 7.

What entity are you spawning?

in this case it was the entity prinny spawned through spawn egg, but when i had the event replacer replace vanilla mobs with custom ones, any one of them would cause that as soon as the world was started if there already were a few replaceable mobs present.

 

most of those custom entities were nearly blank extensions to original mob, only having the main class that would modify their hitbox size.

 

code for the prinny entity:

https://dl.dropboxusercontent.com/u/62600417/Minecraft/etc/ent1.txt

 

code for the blank entity:

https://dl.dropboxusercontent.com/u/62600417/Minecraft/etc/exmob.txt

 

stuff for the event, in preinit:

EntityRegistry.registerModEntity(EntityCMMSpider.class, "Spider", 18, YarrCuteMobModels.instance, 40, 1, true);

 

render, in init:

if (YarrCuteMobModels.SpiderReplaceModel == true)
RenderingRegistry.registerEntityRenderingHandler(EntityCMMSpider.class, new RenderCMMSpiderCMM(new ModelCMMSpider(), 0.3F));

 

and in EntityJoinWorldEvent

				    	if (event.entity.getClass() == net.minecraft.entity.monster.EntitySpider.class)//.getSimpleName() == "EntitySpider")// 
			    	{
			    		EntityCMMSpider spawnEntity = new EntityCMMSpider(event.world);
						Entity entitySrc = event.entity;
				    	spawnEntity.setPosition(event.entity.posX, event.entity.posY, event.entity.posZ);
//				    	spawnEntity.setAngles(event.entity.rotationPitch, event.entity.rotationYaw);
				    	event.world.spawnEntityInWorld(spawnEntity);
						spawnEntity.func_180432_n(entitySrc);
				    	event.entity.setDead();
				    }