This has been the case since December.
How to reproduce:
1. Open Gnome software
2. Click on green menu icon
3. Click on 'software repositories'
result: 'software repositories' wont launch
expected results: you used to see a window appear and you could add or remove ppa and repos you are subscribed to.
Gnome logs gives me this:
23:51:33 gnome-software: aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for PureOS/green
23:51:33 gnome-software: aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for PureOS/green
23:51:33 gnome-software: (self.id, self.codename))
23:51:33 gnome-software: File "/usr/lib/python3/dist-packages/aptsources/distro.py", line 93, in get_sources
23:51:33 gnome-software: self.distro.get_sources(self.sourceslist)
23:51:33 gnome-software: File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 599, in reload_sourceslist
23:51:33 gnome-software: self.reload_sourceslist()
23:51:33 gnome-software: File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 109, in __init__
23:51:33 gnome-software: SoftwareProperties.__init__(self, options=options, datadir=datadir)
23:51:33 gnome-software: File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 109, in __init__
23:51:33 gnome-software: app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)
23:51:33 gnome-software: File "/usr/bin/software-properties-gtk", line 101, in <module>
23:51:33 gnome-software: Traceback (most recent call last):
23:51:33 gnome-software: ERROR:root:Cannot import UbuntuDrivers: No module named 'UbuntuDrivers'