Board Thread:LotR Mod Technical Support/@comment-30553864-20161116231332/@comment-27219153-20161117044852

Okay, so I used the original region file you uploaded and teleported to the coordinates of the spawner, and I crashed instantly. This means it is definitely a problem with your world, rather than graphics drivers.

Upon looking into the NBT data of the spawner, I found that it was missing a value for the tag

This is no doubt the reason why it can't render the spawner and crashes. As for what caused all your spawners to lose that value of their data tag, I have no idea. If someone knew how (which I don't), I think the best solution would be to create an MCEdit filter to find and replace all spawners with air. Otherwise, you are probably going to keep getting these crashes indefinitely.