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An icon has recently appeared on my panel with an exclamation mark. The message i get when hovering over this is that the update information is out of date, and that this may be caused by an unavailable repository or a network isssue.

My network connection appears to be ok.

The message advises i manually check for updates. When i do this, i get the following message:

W:Failed to fetch 404 Not Found , W:Failed to fetch 404 Not Found , E:Some index files failed to download, they have been ignored, or old ones used instead.

Any idea whats going on?

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The best way I have found of solving most problems with "failed to fetch" is to check that you are using the best server. The reason this works is that in the process of selecting the best server it has to ping each of the available servers to find the one that responds the fastest. If there is anything wrong at your end the entire process would probably fail otherwise it my select a different server if the one you normally use is down for maintenance. I personally do this as one of those "after Installation todo's"

  • The function can be found in software sources which can be accessed through the software centre's edit menu

Software Centre Edit menu

  • Then select other from the server menu

Server selection menu

  • And finally hit the Choose the best server button

Choose server dialogue

Hope this helps.

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That said - it would appear that those urls do not exist.

Check that you have up to date information for the ppas you are using.

If any are not correct that will likely be your problem - you can remove the source list for the respective ppas either from software sources - which I think is accessible from the settings options in update manager/software centre or synaptic.

Alternatively they will be listed in /etc/apt/sources.list.d/ and can be removed with rm


sudo rm /etc/apt/sources.list.d/nameoflist.list

Once they have been removed

sudo apt-get update

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