Browsing a long method (lets say, of ~270KB of sourcecode) just hangs the image. Interrupting doesn't even give me control over my image again. It does no open a debugger, but info is printed in stdout, so I assume that my UIProcess died, but the event fetcher is still alive... One of the processes that get interrupted prints: SmallIdentityDictionary(SmallDictionary)>>at:ifAbsent: MorphExtension>>valueOfProperty:ifAbsent: MorphExtension>>valueOfProperty: ScrollBar(Morph)>>valueOfProperty: ScrollBar(Morph)>>theme ScrollBar>>normalThumbFillStyle ScrollBar>>adoptGradientColor: ScrollBar>>sliderColor: ScrollBar>>adoptPaneColor: PluggableMultiColumnListMorph(Morph)>>adoptPaneColor: in Block: [:m | m adoptPaneColor: paneColor] So I just changed #adoptPaneColor: in ScrollBar to do nothing, and I am able to interrupt again. So it makes me think here it is where the UIProcess gets killed... Now, for the browser stuff, it seems that TextComposer>>#composeAllLines never finishes. I'm still investigating, but any clue is helpful :). Guille