I don't know what packages i have installed that i no longer can get and install packages in terminal. e.g. when trying to install Prozgui, i got this error:

Traceback (most recent call last):
  File "/usr/bin/add-apt-repository", line 60, in <module>
    sp = SoftwareProperties()   
  File "/usr/lib/python2.7/dist-packages/softwareproperties/SoftwareProperties.py", line 90, in __init__
    self.reload_sourceslist()
  File "/usr/lib/python2.7/dist-packages/softwareproperties/SoftwareProperties.py", line 538, 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

and it happens for all others too.

Plus, my Software Center has been disabled and doesn't start. I get this error for that too:

Traceback (most recent call last):
  File "/usr/bin/software-center", line 111, in <module>
    from softwarecenter.app import SoftwareCenterApp
  File "/usr/share/software-center/softwarecenter/app.py", line 40, in <module>
    from softwarecenter.db.application import Application, DebFileApplication
  File "/usr/share/software-center/softwarecenter/db/application.py", line 30, in <module>
    from softwarecenter.distro import get_distro
  File "/usr/share/software-center/softwarecenter/distro/__init__.py", line 151, in <module>
    distro_instance=_get_distro()
  File "/usr/share/software-center/softwarecenter/distro/__init__.py", line 140, in _get_distro
    module =  __import__(distro_id, globals(), locals(), [], -1)
ImportError: No module named OPTIMOS

Can anyone please help me with this? Thank you in advance!