Server is vanilla 1.8.3, downloaded directly from minecraft.net. I'm attaching a crash log now. The RPs in question both contain sound effects and one contains a custom language, the application of which triggers the bug most reliably.
This was marked as a duplicate to a rather different bug, even though they are not the same problem. The problem there is that the top of the tree looks strange, the problem here is that the bottom of the tree is in the wrong place.
Killian Long
Server is vanilla 1.8.3, downloaded directly from minecraft.net. I'm attaching a crash log now.
The RPs in question both contain sound effects and one contains a custom language, the application of which triggers the bug most reliably.