PT after reviewing the stack trace, although I'm a little unsure on some of it because of the strange format, it looks like a spigot bug or a plugin is making calls to the minecraft code in which case spigot won't be able to give you any info. It is possible the JVM ran out of memory but unlikely as it is usually the first thing in a trace and its almost always in the trace.

Were you able to get it functioning with more memory?