When using lumbering in a large forest it can cause the server to crash. It seems like it is caused by a StackOverflowError from the recursive method calls in EnchantmentLumberingHandler.java.

Crash report: https://gist.github.com/KalleStruik/a52b3a6491dea860a6ea885ab83b7065

Fixed in 9792fcc, should be out later today :)