I tried to add ( by clicking ) repository’s and they fail
eg ticked multiverse and get this error
Failed to fetch http://packages.netrunner-os.com/dists/frontier-14/InRelease Unable to find expected entry ‘multiverse/binary-amd64/Packages’ in Release file (Wrong sources.list entry or malformed file)
Some index files failed to download. They have been ignored, or old ones used instead.
Multiverse is activated by default for the ubuntu repositories. There is no multiverse in the packages.netrunner-os.com repository.
So I advice you to deactivate that in the /etc/apt/sources.list.d/official-*.list file by removing the multiverse from this particular line. You need superuser rights to edit this file (e.g. Execute kdesudo kate to open up kate with superuser rights)
The problem is where synaptic is placing the ticked repositories in the setup. It is adding it to the netrunner line and not enabling the correct repository.
deb http://packages.netrunner-os.com frontier-14 main (synaptic is adding it here) #id:netrunner_main
Best it you open the file to see if the repository you want is enabled manually.
and when you update the repository open up the details and make sure you see it updated.
I am not by the distro now so I can only suggest that you open a terminal and
sudo dolphin and then go to the folder /etc/apt/sources.list.d/ and look in official-*.list file with kate and look for a file similar to the one I have above.