From the logs:

[2014-07-08T09:54:43.97] Exception in thread "ThreadNotStartedInterrupter #163" java.lang.OutOfMemoryError: unable to create native thread: possibly out of memory or process/resource limits reached
[2014-07-08T09:54:43.97] at java.lang.Thread.start0(Native Method)
[2014-07-08T09:54:43.97] at java.lang.Thread.start(Thread.java:714)
[2014-07-08T09:54:43.97] at runtime.threads.ThreadInterruptedNotStarted.ThreadNotStartedInterrupter.run(ThreadInterruptedNotStarted.java:91)
[2014-07-08T09:54:43.99] Exception in thread "ThreadNotStartedInterrupter #165" java.lang.OutOfMemoryError: unable to create native thread: possibly out of memory or process/resource limits reached
[2014-07-08T09:54:43.99] at java.lang.Thread.start0(Native Method)
[2014-07-08T09:54:43.99] at java.lang.Thread.start(Thread.java:714)
[2014-07-08T09:54:43.99] at runtime.threads.ThreadInterruptedNotStarted.ThreadNotStartedInterrupter.run(ThreadInterruptedNotStarted.java:91)
...