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W:Failed to fetch http://ppa.launchpad.net/plushuang-tw/uget-stable/ubuntu/dists/saucy/main/binary-i386/Packages 404 Not Found , E:Some index files failed to download. They have been ignored, or old ones used instead.

marked as duplicate by Eric Carvalho, Charles Green, Fabby, waltinator, Pablo A Apr 10 at 15:25

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run these commands in terminal,

sudo apt-get update
sudo apt-get -f install

And also check your internet connection.

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