We have a test build for pharo5 that checks if we need to do stuff for future migrations. Since yesterday it fails, of course. I have a fueled out object graph stored as byte array in a method. The fuel bytes are serialized using a non-spur image. Now when the spur image reads the bytes I get an exception. Has this something to do with immediate characters? Is there a way to fix that or will it just not be possible to exchange objects between spur and non-spur using fuel? thanks, Norbert primitive #value: in Character class failed Stacktrace Character class(Object)>>primitiveFailed: Character class(Object)>>primitiveFailed Character class>>value: Character class>>materializeFrom: FLHookPrimitiveCluster>>materializeInstanceWith: FLHookPrimitiveCluster(FLIteratingCluster)>>materializeInstancesStepWith: FLMaterialization>>clusterInstancesStep [ self clusterInstancesStep ] in FLMaterialization>>instancesStep SmallInteger(Integer)>>timesRepeat: FLMaterialization>>instancesStep FLMaterialization>>run [ :aDecoder | (FLMaterialization with: aDecoder) run; yourself ] in FLMaterializer>>setDefaultMaterialization FLMaterializer>>materializeFrom: FLMaterializer class>>materializeFromByteArray: MAPExampleModels class>>readModelFromSelector: MAPExampleModels class>>readModelNamed: [ self readModelNamed: aString ] in MAPExampleModels class>>named: [ self at: key put: aBlock value ] in Dictionary>>at:ifAbsentPut: Dictionary>>at:ifAbsent: Dictionary>>at:ifAbsentPut: MAPExampleModels class>>named: MAPTest>>model MAPTest>>tcapModule MAPTest>>testInsertSubscriberDataBitStringAccess [ testMethod perform: testMethod selector ] in Given>>produceReturnValueAt: [ self at: key put: aBlock value ] in Dictionary>>at:ifAbsentPut: Dictionary>>at:ifAbsent: Dictionary>>at:ifAbsentPut: Given>>produceReturnValueAt: MAPTest(Phexample)>>performTest