Hi all, I don't post to lists often, but I thought some of you might be interested in these few lines of code that crash the CogVM on both Linux and Windows. File-in the Smalltalk code below, then evaluate [nil crashCogVM]. The code uses [1-1] but it could use [1+1] or [56+98]. I put the code on nil, but that is not important either. I think the important thing is that the primitive (+ or -) is evaluated but the result is not assigned into any variable. Also important is that the code is put into a loop that I assume has been JIT optimized. The image I used is Pharo 1.4 one-click with latest update #14459. This code does not crash StackVM. Have fun! - Jon. !UndefinedObject methodsFor: 'crash' stamp: 'JonKAnderson 11/29/2012 17:26'! crashCogVM " Evaluate [ nil crashCogVM ]" | i | i := 20. 1 to: i do: [:d | 1-1 ] ! !