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The problem is you execute the updateStorageBlock method recursively, which leads to the execution of the update method and there you add a new tile entity to your list you currently iterating over. This leads to the thrown ConcurrentModificationException because it's not allowed to modifie a list you currently iterating over. A simple fix would be copy the content of the list in a new list and iterate over this copy instead of the original one. But this fix only works if you not need the newly added tile entities.

You need to read up on sides. You can't directly access minecraft in your mod constructor like that, as the server has no idea what the client Minecraft class is.

You never assign the objects in your BlocksList class to anything.

Are you running Optifine? If so, remove it.