app = SoftwarePropertiesKDE(datadir=data_dir, options=options, file=afile, attachWinID=attachWinID) File "/usr/lib/python3/dist-packages/softwareproperties/kde/SoftwarePropertiesKDE.py", line 62, in __init__ SoftwareProperties.__init__(self, options=options, datadir=datadir) File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 128, in __init__ self.reload_sourceslist() File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 623, in reload_sourceslist self.distro.get_sources(self.sourceslist) File "/usr/lib/python3/dist-packages/aptsources/distro.py", line 93, in get_sources (self.id, self.codename)) aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for neon/bionic
neon-settings (IIRC) contains templates/neon which defines "versions", this needs importing of the ubuntu versions up to bionic