Still working on converting from Version 3.0.4 to 3.1.M1. Am seeing the exception below. Modified DefaultFactHandle as follows to fix it. public String toExternalForm() { if(shadowFact) { Object objOut = ((ShadowProxy)object).getShadowedObject(); return "[fid:" + this.id + ":" + this.recency + ":" + objOut + "]"; } else { return "[fid:" + this.id + ":" + this.recency + ":" + this.object + "]"; } } Exception in thread "CheckLauncher" java.lang.IncompatibleClassChangeError at com.nortel.connect.model.common.NodeWrapperIfShadowProxy.toString(Unknow n Source) at java.lang.String.valueOf(Unknown Source) at java.lang.StringBuilder.append(Unknown Source) at org.drools.common.DefaultFactHandle.toExternalForm(DefaultFactHandle.jav a:110) at com.nortel.connect.rulesengine.inferengine.FactsHandler.addFact(FactsHan dler.java:149) at com.nortel.connect.rulesengine.CheckManager$CheckTask.addTask(CheckManag er.java:557) at com.nortel.connect.rulesengine.CheckManager$CheckTask.doCheck(CheckManag er.java:540) at com.nortel.connect.rulesengine.CheckManager$CheckTask.access$2(CheckMana ger.java:535) at com.nortel.connect.rulesengine.CheckManager.runChecks(CheckManager.java: 368) at com.nortel.connect.rulesengine.CheckManager.access$3(CheckManager.java:3 65) at com.nortel.connect.rulesengine.CheckManager$Launcher.run(CheckManager.ja va:462) at java.lang.Thread.run(Unknown Source) For some reason I got a ShadowFact in the FactHandle. Only saw one case of this out of many activation created events. Can you tell me when this will be the case? Also had to remove modifyFacts to get activations to be created? Any idea why? My concern is that we will miss evaluate (skip rule violations) our facts since in version 3.0.4 we had to modify facts to get all evaluations required. Thanks. Regards, Tom G Tom Gonzalez NortelNetworks Cost Improvement Tools Software Design tomgon(a)nortel.com 919-905-8656