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Possible Duplicate:
How do I deal with “unauthenticated sources” errors in the Software Center?

I'm trying to install software updates but I always get this error.

Requires installation of untrusted packages
The action would require the installation of packages from unauthenticated sources.
Details : gir1.2-mutter-3.0 gnome-tweak-tool libmutter0 mutter-common

I don't know what it's asking me to do. Please help.


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marked as duplicate by Jorge Castro, hexafraction, Eliah Kagan, maythux, Mitch Oct 8 '12 at 5:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Can you post the output of sudo apt-get update in your question? – cauon Oct 5 '12 at 7:59
Did you check this ?… – mac Oct 5 '12 at 8:00

This actually solved the problem:

sudo apt-get clean

cd /var/lib/apt

sudo mv lists lists.old

sudo mkdir -p lists/partial

sudo apt-get clean

sudo apt-get update

Many thanks!

I got the answer here: How do I deal with "unauthenticated sources" errors in the Software Center?

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Just "sudo apt-get clean" and "sudo apt-get update" was sufficient for me. – David Easley Mar 21 '14 at 19:42

You can try to select a differnent mirror. Run

sudo software-properties-gtk

In the Ubuntu Software tab, Download from, select via the drop-down an other server. After this, run

sudo apt-get update

Hopefully this will resolve your issue.

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