Comment 38 for bug 1053749

I am also experiencing this issue on a Mint Linux 14 Cinnamon. I tried finding invalid characters in the files listed but there were none. I saved each file with gedit which did not help. I did have davmail installed for a day, but I uninstalled it before this error started.

software-properties-gtk --debug
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 9: reading configurations from ~/.fonts.conf is deprecated.
gpg: /tmp/tmpoqfkhc/trustdb.gpg: trustdb created
ENABLED COMPS: {'import', 'main', 'backport', 'upstream'}
INTERNET COMPS: {'import', 'main', 'backport', 'upstream'}
MAIN SOURCES
 URI: http://packages.linuxmint.com/
 Comps: ['main', 'upstream', 'import', 'backport']
 Enabled: True
 Valid: True
 MatchURI: packages.linuxmint.com
 BaseURI: http://packages.linuxmint.com/

CHILD SOURCES
CDROM SOURCES
SOURCE CODE SOURCES
DISABLED SOURCES
ISV
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/UbuntuDrivers/detect.py", line 162, in packages_for_modalias
    cache_map = packages_for_modalias.cache_maps[apt_cache_hash]
KeyError: 3953453

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/software-properties-gtk", line 103, in <module>
    app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 178, in __init__
    self.init_drivers()
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 1097, in init_drivers
    self.devices = detect.system_device_drivers()
  File "/usr/lib/python3/dist-packages/UbuntuDrivers/detect.py", line 415, in system_device_drivers
    for pkg, pkginfo in system_driver_packages(apt_cache).items():
  File "/usr/lib/python3/dist-packages/UbuntuDrivers/detect.py", line 319, in system_driver_packages
    for p in packages_for_modalias(apt_cache, alias):
  File "/usr/lib/python3/dist-packages/UbuntuDrivers/detect.py", line 164, in packages_for_modalias
    cache_map = _apt_cache_modalias_map(apt_cache)
  File "/usr/lib/python3/dist-packages/UbuntuDrivers/detect.py", line 129, in _apt_cache_modalias_map
    m = package.candidate.record['Modaliases']
  File "/usr/lib/python3/dist-packages/apt/package.py", line 429, in record
    return Record(self._records.record)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xeb in position 74: invalid continuation byte