The code was not handling "errorParameters" properly when they were not passed. This was resulting in errors like NPE
at org.jaffa.rules.jbossaop.interceptors.AbstractRuleInterceptor.invoke(AbstractRuleInterceptor.java:156)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) when a rule wanted to throw an exception.