Thanks for that - my graylog.list file was empty. Uninstalling the 4.3 repo latest.deb file and reinstalling it still left this file empty. Not sure exactly what the install of this file should do - but I’m guessing it SHOULD update this graylog.list file with the proper repo, since after I added it manually as you instructed - my update and upgrade commands work and it’s currently updating to 4.3 now.