Software Updater Issue 16.04

Whenever I click on software updater it says Failed to download repository information.

It's been saying this for the past few days now and I don't know why, my Internet connection is fine, I am able to manually download software.

Sometimes it crashes when I click okay, then attempts to look for updates again and gives me the same message.

Any ideas?

[EDIT] I just tried an answer posted where I reset where the downloads come from, but I was left with this message:

W:The repository 'http://ppa.launchpad.net/noobslab/noobslab-conky/ubuntu xenial Release' does not have a Release file., 
W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., 
W:See apt-secure(8) manpage for repository creation and user configuration details., 
W:https://content.runescape.com/downloads/ubuntu/dists/trusty/InRelease: Signature by key AAC9264309E4D717441DB9527373B12CE03BEB4B uses weak digest algorithm (SHA1), 
E:Failed to fetch http://ppa.launchpad.net/noobslab/noobslab-conky/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found, 
E:Some index files failed to download. They have been ignored, or old ones used instead.

Solution 1:

Open Software & updates

Change the server from Download from:

For best download speed choose your country or a country next to you. Alternatively, let ubuntu test and decide the fastest server by clicking the Select best server button.

Solution 2:

Your basic problems are with two PPAs that you're using, the Noobslab and Netscape repos. The error that you get with netscape is just a warning; it won't break your update process. However the Noobslab repo is not compatible with your Ubuntu version (16.04) so you need to delete this source from Software & Sources > Other Software

After doing this step you should be able to update everything.

See error details from these posts:

How to fix apt: Signature by key uses weak digest algorithm (SHA1)?

How can I fix a 404 Error when using a PPA or updating my package lists?