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The Update Manager hasn't been working properly for a while. I've got a number of updates that've stacked up, because of this very problem. Each time that I go for installing the updates, i get a message saying that the updates contain untrusted packages, however that cannot be the case, all the additional PPAs that have been added, i've done them myself, and till some time back they used to work perfectly, now however things are different. I'm posting images of the Update manager, the error message and i'll enter the error details below.

Any help would be great.

Update Manager

Update Manager



Error Details

apport apport-gtk bash-completion cups cups-bsd cups-client cups-common cups-ppdc dbus dbus-x11 flashplugin-installer google-chrome-stable gvfs gvfs-backends gvfs-bin gvfs-common gvfs-daemons gvfs-fuse gvfs-libs isc-dhcp-client isc-dhcp-common kdelibs-bin kdelibs5-data kdelibs5-plugins kdoctools libcups2 libcupscgi1 libcupsdriver1 libcupsimage2 libcupsmime1 libcupsppdc1 libdbus-1-3 libfs6 libgnutls-dev libgnutls-openssl27 libgnutls26 libgnutlsxx27 libgstreamer-plugins-base0.10-dev libgstreamer0.10-dev libkcmutils4 libkde3support4 libkdeclarative5 libkdecore5 libkdesu5 libkdeui5 libkdewebkit5 libkdnssd4 libkemoticons4 libkfile4 libkhtml5 libkidletime4 libkio5 libkjsapi4 libkjsembed4 libkmediaplayer4 libknewstuff3-4 libknotifyconfig4 libkntlm4 libkparts4 libkpty4 libkrosscore4 libktexteditor4 liblightdm-gobject-1-0 libnepomuk4 libnepomukquery4a libnepomukutils4 libplasma3 libplymouth2 libpulse-mainloop-glib0 libpulse0 libpulsedsp libraw5 libsolid4 libthreadweaver4 libtiff4 libtiff4-dev libtiffxx0c2 libx11-6 libx11-data libx11-dev libx11-doc libx11-xcb1 libxcb-composite0 libxcb-dri2-0 libxcb-glx0 libxcb-randr0 libxcb-render0 libxcb-render0-dev libxcb-shape0 libxcb-shm0 libxcb-shm0-dev libxcb-sync0 libxcb-xfixes0 libxcb-xv0 libxcb1 libxcb1-dev libxcursor-dev libxcursor1 libxext-dev libxext6 libxfixes-dev libxfixes3 libxi-dev libxi6 libxinerama-dev libxinerama1 libxp6 libxrandr-dev libxrandr2 libxrender-dev libxrender1 libxres1 libxslt1-dev libxt-dev libxt6 libxtst6 libxv1 libxvmc1 libxxf86dga1 libxxf86vm1 lightdm linux-image-3.2.0-48-generic-pae linux-image-generic-pae linux-libc-dev plymouth plymouth-label plymouth-theme-ubuntu-logo plymouth-theme-ubuntu-text pulseaudio pulseaudio-module-bluetooth pulseaudio-module-gconf pulseaudio-module-x11 pulseaudio-utils python-apport python-apt python-apt-common python-paramiko python-problem-report rsyslog telepathy-gabble xdiagnose xserver-xorg-video-openchrome


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I found that installing Muon Software Updater then running muon-updater skips, but reports errors, rather than failing. – SimplySimon Jun 19 '13 at 7:55
up vote 1 down vote accepted

Write in terminal:

sudo apt-get update && sudo apt-get upgrade 

or you could

edit Update Manager settings

Click on the settings button in update manager and go to updates tab make sure that recommended and important updates are ticked

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as there are over 500 updates pending, this could take a huge amount of time, but worth a try :) – SimplySimon Jun 19 '13 at 7:57
This error can also be caused by missing Public Keys..It will be helpul if you post the output of sudo apt-get update if the above methods dont work – Stormvirux Jun 19 '13 at 8:09
Stick to first command, until issue identified: type sudo apt-get update and report on the 'key' errors. – david6 Jun 19 '13 at 8:57
@SimplySimon I ran the command but it didn't work, here's the output 'W: Failed to fetch Unable to find expected entry 'non-free/source/Sources' in Release file (Wrong sources.list entry or malformed file) E: Some index files failed to download. They have been ignored, or old ones used instead.' – Projjol Jun 19 '13 at 11:41
@Projjol,In the update manager settings ,take the other software tab and uncheck running sudo apt-get update again. – Stormvirux Jun 19 '13 at 12:51

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