I had been looking at what the "404 challenge" was and I happened to find the world on planetminecraft. I downloaded it, booted MC, and loaded the level. about 7 seconds after loading, I saw the world, and then it crashed. The crash is in the files.
According to the crash, an invalid propery was set on a chest?
<code>
java.lang.IllegalArgumentException:
Cannot set property
ayl{name=facing, clazz=class dt, values=[north, south, west, east]}
to down on block minecraft:chest, it is not an allowed value
</code>
Please give us a link to the map you used or attach it, so that we can check this.