I have been trying to download Mountain Lion 10.8.5 from the Apple App Store and it hangs consistently after 154MB on 2 different computers. Apple are working on the issue and think that it may be associated with my router (details below). Has anyone come across this issue? Other Apps download fine.
There wouldn't be anything on the router itself blocking that download from the App Store. Would it be possible to try on a different network (even a mobile network if possible) to see if that allows the download?