Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file [duplicate]

Solution 1:

The PPA has no packages for the version of Ubuntu (16.04) you are running and so no Release file. The Release file is used to check the integrity of packages from a source, so APT treats this as a security issue and refuses to fetch anything.

Possible causes of having a broken PPA:

• you recently upgraded and the PPA was not removed
• you installed offline (I've experienced this strangely adding outdated PPAs to sources)
• another user added the PPA without your knowledge

The best way to remove a PPA you have installed packages from is with ppa-purge which also removes any associated packages and attempts to return them to default versions

sudo apt install ppa-purge
sudo ppa-purge ppa:izx/askubuntu/ubuntu

But if you don't have any packages from the PPA (as in this case), you can simply use the add-apt-repository command with the -r remove flag:

sudo add-apt-repository -r ppa:izx/askubuntu/ubuntu

Or just delete the file for it in /etc/apt/sources.list.d