I thought I saw some problems on the list a few days ago with 6.6 so I'm not sure whether this is a repeat or not. I've just installed 6.6.0 and can not associate Livesocde stacks with it. Even after uninstalling 6.5.2 I get hung when choosing Livecode 6.6.0 via the properties window as the 'open with' for a stack. I'm using Windows 8.1 Thanks, Ray