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apt-get i get the following error :-
W: GPG error: https://dl.bintray.com Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 99E82A75642AC823 W: Failed to fetch http://ppa.launchpad.net/picaso/octave/ubuntu/dists/trusty/main/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ppa.launchpad.net/picaso/octave/ubuntu/dists/trusty/main/binary-i386/Packages 404 Not Found W: Failed to fetch http://ppa.launchpad.net/samrog131/ppa/ubuntu/dists/trusty/main/binary-amd64/Packages 404 Not Found W: Failed to fetch http://ppa.launchpad.net/samrog131/ppa/ubuntu/dists/trusty/main/binary-i386/Packages 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.
I have tried a number of solutions each of which failed. I can't install any software using
sudo apt-get update in their script now :(
I have already tried system updates, trying to contact the keyserver (which always returns a timeout)