Why do you have a totally outdated version of Firefox 52.3.0 in your netrunner 19.01 repositories? This version is no more maintained:
. In Debian testing there is the version 60.5.0. You can not see this version, because the netrunner backports hide the testing version. In my opinion this very dangerous to offer an outdated version of Firefox 52 ESR the same is valid to Firefox 65, because the latest release patches security issues. You should announce that to your customers, that there will be no Firefox 65 at netrunner 19 repositories.
Thanks for reporting. This should not be the case. I removed Firefox and Firefox-ESR from the backports repository. If it is still there after an apt update we need to resync the repositories.
I will keep you updated on this.
edit: Just resynced the netrunner-backports repository. Firefox-ESR should be gone from it now. Please test and report if it works for you.
Now it works, but Firefox 60.0.5 ESR complains about “failed to read the configuration file”. I have installed your Firefox 64.0 parallel. What can I do to get rid of this error?
I read the Debian security alerts and so I suggest that you remove Firefox 64 from your repositories and to deliver in the future the ESR version from Debian, because I think that you are interested highly that all users of your great Distro stay safe, not every user thinks about her/his system and so they are not aware of the risks of an outdated browser. Kind regards.
Please look here: https://www.debian.org/News/2019/20190216 what do you mean concerning your repositories?
Thank you.
Yes noted. We will take a look at that for future releases.
How I can repair the error message of Firefox ESR “Failed to read the config file…”. It’s very annoying because every time when Firefox starts, I see this message.
Edit the file /usr/lib/firefox-esr/defaults/pref/autoconfig.js and replace the filename cck2.cfg with netrunner.cfg
Thank you. Are you supporting neptune too, will this distro updated too, when Debian buster is the new stable release?
Yes I am the main developer of Neptune. Neptune 6 Beta ISO is already on our download server. An upgrade script is available for testing aswell. The rest you can discuss on the Neptune Forum I would suggest 
Thank you. The error is gone. I uninstalled Firefox 64 and set firefox ESR as default browser. How I can get rid of Thunderbird 45.8.03 and install the latest version 60.xx without dependency issues?
Please create a new thread for this.