Hi folks. I am trying to do something and I found a VM crash. Suppose I want to swap out a class, do a become with a proxy (that with the DNU will load the class back). In addition, I have instances of the swapped class. Example of code (will crash in the last line): o := MyObject new. o foo: 123. p := ClassProxy new. p become: MyObject. o == nil. o foo. My Object just extends Object, has an instVar 'foo', and implements the accessors. ClassProxy implements: become: aClass className := aClass name. aClass fileOut. super become: aClass and doesNotUnderstand: aMessage | reloadedClass | (FileStream fileNamed: className, '.st') fileIn. reloadedClass := Smalltalk at: className. self becomeForward: reloadedClass. ^aMessage sendTo: reloadedClass So....does someone know why the crash? how can I solve it ? Thanks in advance Mariano