TheRealMcrafter

Correct me if i'm wrong, but players don't use SharedMonsterAttributes, because player != monster

Can you post the class where you register your tile entity?

Can you post your tile entity class and the crash report please?

Code would be helpful

You are setting the inventory slot with your item, and then getting the item you just set. You want to do this: ItemStack slotStack = inventory.getStackInSlot(slot); ItemStack currentStack = inventory.getStackInSlot(inventory.currentItem); if (slotStack != null){ inventory.setInventorySlotContents(inventory.currentItem, slotStack); } else { //return here? if you want to } if (currentStack != null){ inventory.setInventorySlotContents(slot, currentStack); } else { //same as above } Also, I dont know if you can do these operations on the client side, since you are using Minecraft.getMinecraft().thePlayer (client side player)

I'd suggest studying in depth EntityAIOwnerHurtByTarget and EntityAIOwnerHurtTarget

Okay, well coolAlias' point still goes, you dont need to make 2 threads about the same thing.

As coolAlias pointed out, he already told you in your other thread that was "SOLVED 100%" that you are not handling cases where the entity can be null.

Also, there isnt any EntityUndead class in 1.7.10 this.tasks.addTask(5, new EntityAIWatchClosest(this, EntityUndead.class, 1.0F)); Do you see any red squares on the right side of your class file?

I believe he wants an auto killing mod, where as long as there is an entity in the crosshairs, attack it (like for a blaze farm, in his case)

Listen to what people are telling you.... if (!this.getAggressive()) { means if this.getAggressive equals false which means as long as the mob IS NOT aggressive, do the following block of code

Really? A bump after 2 hours?

It actually crashes on expand(10, 10, 10)

You do not handle a case where Minecraft cannot find any entities. What is on this line? at com.ferret.myfirstmod.items.ItemIceMask.onArmorTick(ItemIceMask.java:86) EDIT: Woops, i'm blind. I see it.

Try naming them something like SteamEngineWaterPortChanged, then back to steamEngineWaterPort I had this before, where I had SiliconOre, so I renamed it to siliconOre. Didn't fix the problem. Put it back to SiliconOre, then added something onto it. Then reverted it back to normal.