what ppa should be removed to not get apt-get update error
133
How can I fix a 404 Error when using a PPA or updating my package lists?
76256
apt-get removed, how to reinstall it?
102441
Having trouble with apt-get upgrade and removing KDE Plasma
93942
How to fix "Failed to download repository information" error while updating?
15183
Elementary OS PPA gives “The repository does not have a Release file.” error
16753
Why should I regularly run 'apt-get update' and similar commands?
10101
How can PPAs be removed?
155198
What is the difference between the "jessie" and "jessie-updates" distributions in /etc/apt/sources.list?
40219
Remove all packages installed from a PPA?
45292
How to install removed apt
34720
What is the difference in command-line "sudo apt-get update" and using Synaptic or Auto-updater?
112870
How can I remove all build dependencies for a particular package?
109624
How do I tell apt to never upgrade a particular package?
135985
Apt-get saying "Unable to correct problems, you have held broken packages."
64970
How to exclude a package from apt-get autoremove?
65099
Unable to install any updates through update manager/apt-get upgrade
96696
timeout errors in apt-get update/install