After deleting a ppa entry in the sources.list file, I was not able to open the software sources application. Opening the software centre is fine. I tried running gksudo software-properties-gtk and got the follwong message: SoftwareProperties.__init__(self, options=options, datadir=datadir) File "/usr/lib/python2.7/dist-packages/softwareproperties/SoftwareProperties.py", line 96, in __init__ self.reload_sourceslist() File "/usr/lib/python2.7/dist-packages/softwareproperties/SoftwareProperties.py", line 580, in reload_sourceslist self.distro.get_sources(self.sourceslist) File "/usr/lib/python2.7/dist-packages/aptsources/distro.py", line 91, in get_sources raise NoDistroTemplateException("Error: could not find a " aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template Would appreciate if you can let me know how to solve this problem.