Unable to add ppa:nathan-renniewaldock/flux in Ubuntu 18.10 cosmic

[pragun]

Re: Update Ubuntu's PPA
I have installed Kubuntu and I am trying to add this ppa for installing f.lix GUI but it throwsn an error while adding ppa:
Err:7 http://ppa.launchpad.net/nathan-renniewaldock/flux/ubuntu cosmic Release
404 Not Found [IP: 91.189.95.83 80]

[sfsurfer]

I just ran into this. It is available in 18.4 bionic, so if you edit the sources file: /etc/apt/sources.list.d/nathan-renniewaldock-ubuntu-flux-cosmic.list, and change cosmic to bionic on the first line, you'll be able to install it.