Hi Igor, Besides some other small comits, in NativeBoost-Core-CiprianTeodorov.103 I have changed the way anonymous subclasses of NBExternalTypeValue and NBExternalArray are created. The reason is that using the old way we would create multiple instances of the same metaclass which is not allowed in the image. BTW, I was getting this problem when trying to modify (add or remove) class instance variables of the NBExternalArray. Doing NBExternalArray class allInstances, I was clearly getting more than one instance... Now the anonymous subclasses are build using ClassBuilder>>#newSubclassOf:type:instanceVariables:from: which seems to prevent this problem from happening. What do you think? Are there other ways to get around this problem? Cheers, -- Dr. Ciprian TEODOROV Ingénieur Développement CAO tél : 06 08 54 73 48 mail : ciprian.teodorov@gmail.com www.teodorov.ro