I seem to be having exactly the issue with 5.1.1 described in https://issues.jboss.org/browse/JBRULES-2796 "NullPointerException in FromNode.destroyCreatedHandles"
I can reproduce this problem at will, and I'm willing to try to produce a minimal test case, but to do so would take some significant work. My fact model is moderately complicated and the triggering condition for me seems to be a combination of rules and (updating) facts.
Is there any benefit to my spending the time to develop a test case? Or is this bug already being worked somewhere else?