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I'm using Ubuntu 12.10. Yesterday I noticed that software-properties-gtk does not work anymore. I have no idea why and what to do. When I start via Terminal I get the following output:

chocobai@pfubuntu:~$ software-properties-gtk 
gpg: /tmp/tmpgkhlnl/trustdb.gpg: trust-db erzeugt
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/UbuntuDrivers/", line 162, in packages_for_modalias
cache_map = packages_for_modalias.cache_maps[apt_cache_hash]
KeyError: 4726621

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/", line 178, in __init__
File "/usr/lib/python3/dist-packages/softwareproperties/gtk/", line 1097, in init_drivers
self.devices = detect.system_device_drivers()
File "/usr/lib/python3/dist-packages/UbuntuDrivers/", line 415, in system_device_drivers
for pkg, pkginfo in system_driver_packages(apt_cache).items():
File "/usr/lib/python3/dist-packages/UbuntuDrivers/", line 319, in system_driver_packages
for p in packages_for_modalias(apt_cache, alias):
File "/usr/lib/python3/dist-packages/UbuntuDrivers/", line 164, in packages_for_modalias
cache_map = _apt_cache_modalias_map(apt_cache)
File "/usr/lib/python3/dist-packages/UbuntuDrivers/", line 129, in _apt_cache_modalias_map
m = package.candidate.record['Modaliases']
File "/usr/lib/python3/dist-packages/apt/", line 429, in record
return Record(self._records.record)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfc in position 777: invalid start byte

What I want to do is to completely reinstall the proprietary ATI graphic drivers, because the game DungeonDefenders does not start. Also software-properties-gtk is useful to manage repositories.

I thought about to apt-get purge software-properties-gtk but I'm not sure whether this is safe or I'd break something.

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up vote 1 down vote accepted

I had the same problem but clearing cache didn't sort it. It turned out to be a known issue. Read through it, I could fix it doing the following:

  1. to find the offending character:

    iconv -f utf8 -t ucs-2le /var/lib/dpkg/status  >/dev/null || echo "non-UTF-8 found"
  2. removing the offending non-UTF8 character, you should be able to find the character with vim or nano from the line number reported above.

Hope that helps.

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I used nano. Your command didn't work correctly, though. Maybe because there were several characters wrong. But I found them. I noticed that the wrong characters were caused by the official repository of "back to the roots (bttr)", an "the settlers2" clone. I removed the repository, searched for the word "settler", this way I found the characters really fast. Gedit and find/replace would have surely been faster. Or a Script. All characters were supposed to be a 'ü', but were broke somehow. But everything works now. – verpfeilt Jan 5 '13 at 23:52

It seems your local cache is corrupted. You can try running sudo apt-get update to update the cache. If that fails, you may need to clean out /var/cache/apt/ and then run sudo apt-get update to recover.

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