Hi guys. I am running some tests with Fuel. In such test I create classes and traits. The problem is that I get a: "MessageNotUnderstood: receiver of "isProvided" is nil" Everything starts (it seems) when I do #addToComposition: and I receive a MethodRecategorized event and RPackage calls #systemMethodRecategorizedActionFrom: There, the problem is with -> method isProvidedByATrait the class of the method is 'AnObsoleteClassForTestToBeDeleted1' And the error finally arrives to #providedLocatedMethod where it does "each method isProvided" the problem is that "each" is a RGMethodDefinition with everything in nil except 'name' and 'annotations'. I attach PharoDebug.log. Any help is really appreaciated. Thanks, -- Mariano http://marianopeck.wordpress.com