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W:The repository 'http://ppa.launchpad.net/tualatrix/next/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., 
E:Failed to fetch http://ppa.launchpad.net/tualatrix/next/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.
Zanna
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Aravind
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1 Answers1

1

First, those are mostly warnings with one error.

If you read them it tells you the problem:

E:Failed to fetch 
 http://ppa.launchpad.net/tualatrix/next/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.

The maintainer of the PPA does not have a package for xenial.

Either

  1. contact the maintainer - https://launchpad.net/~tualatrix/+archive/ubuntu/next

  2. Disable the PPA and find another source for the package(s) you want.

Zanna
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Panther
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  • Ubuntu Tweak is dead. No updates since early 2015 therefore you're #1 is a waste of time. –  Aug 16 '17 at 18:15