I upgraded to 11.04 today. I had some problems when the system froze with 2 minutes to go; I was forced to do a hard reboot, but the system appeared to work OK. (described here: https://askubuntu.com/questions/40295/distribution-upgrade-froze-my-system)

As the system hadn't been cleaned up before rebooting, I ran Computer Janitor, but had to stop it when I saw it was deleting things I needed to keep (e.g. Faenze icons vanished). Since then I have been unable to install anything via apt-get, Synaptic or Software Centre. I can add PPAs, but attempting to install anything returns the following message:

E: Sub-process /usr/bin/dpkg returned an error code (1)

The only way I can install anything is by downloading the deb and installing manually.

Trying to install with the Software Centre causes a window to open saying "An unhandled error occurred). Clicking on "details" reveals the following:

Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 961, in simulate trans.unauthenticated = self._simulate_helper(trans) File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 1085, in >_simulate_helper return depends, self._cache.required_download, \ File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 226, in required_download pm.get_archives(fetcher, self._list, self._records) SystemError: E:I wasn't able to locate file for the rec-applet package. This might mean >you need to manually fix this package.

However, when I try to repost the problem, another window opens with the title "Problem in aptdaemon" and

The problem cannot be reported:

You have some obsolete package versions installed. Please upgrade the following >packages and check if the problem still occurs:


EDIT - I tried Jordy's solution. When I then checked for local or obsolete packages in Synaptic, one was marked in red and marked for removal (rec-applet). When I attempt to remove it, I get the message:

E: rec-applet: subprocess installed post-removal script returned error exit status 1

It's as if that was blocking everything else, but there doesn;t seem to be a way of removing it.

EDIT 2 - I remived the offending package following the instructions here: http://www.khattam.info/solved-subprocess-pre-removal-script-returned-error-exit-status-2-error-2009-08-04.html

I feel a bit dirty but it did work, and no need to reinstall the OS.

  • It is not my usually used advice but I would seriously consider reinstalling your OS. This 'I had some problems when the system froze with 2 minutes to go; is not good and you might run into another problem after fixing this one. I support your effort though in trying to fix it without reinstalling though! – Rinzwind May 5 '11 at 13:43

Probably you have broken packages, type: sudo dpkg --configure-a


Regarding this specifically: E: Sub-process /usr/bin/dpkg returned an error code (1)

I found a possible solution mentioned in this message here

  • Try apt-get -f install to force an install of the files that didn't get loaded because of the error. Then try apt-get upgrade again, apt-get -f install back and forth until only the package that has the error is left.

It is a post based on Debian but this also is valid for Ubuntu.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.