UIThemeVistary beCurrent.
what is nice is that the VM does not crash. I cannot open any browser. So in another image I checked a bit. BlockContext defined isValid (a polymoprph-EventEnhancements) sent by BlockContext>>isValid "Answer true so we can be used in event dispatching." ^true WeakActionSequence>>asMinimalRepresentation | valid | valid := self select: [:e | e isValid ]. valid size = 0 ifTrue: [^nil]. valid size = 1 ifTrue: [^valid first]. ^valid I do not really know the code of gary. As a pure hack I added isValid to blockClosure to return true and I did not get the problem of course this is a shitty way to answer the problem. Now when I close using the cross on the right (and not the button on the left) the vistaryStyle I get similar problems [closure] in UIThemeVistary>>createCloseBoxFor: DNU asMinimalRepresentation BlockContext>>asMinimalRepresentation "Answer the receiver." ^self I defined the same in BlockClosure and it worked but I would prefer to understand what I was doing. stef