Any Exception of the Java Virtual Machine will cause RE NZEC. This includes, but is not limited to, uncaught exceptions thrown by your classes and standard classes (including class/method reflection), and critical errors of various elements of the JVM (e.g. out-of-memory error, out-of-stack-space error, cannot-write-to-file error, cannot-find-startup-class error, all sorts of garbage collector errors). Try not to access weird elements of the SUN Java environment (e.g. locale files, time zone information, graphics), as these are not guaranteed to work.