pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

[Patrik Nilsson]

Today I manually checked for updates with update manager. The 'check' for updates worked well and when I was going to install the updates. First time I was asked for the password, I entered an invalid one.

Then I got errors when I was trying to install. See below. It was all solved by: "sudo dpkg --configure -a". Synaptic couldn't solve it.

patrik@ubuntu:~$ lsb_release -rd
Description: Ubuntu 11.04
Release: 11.04
patrik@ubuntu:~$ apt-cache policy update-manager
update-manager:
  Installed: 1:0.150.3
  Candidate: 1:0.150.3
  Version table:
 *** 1:0.150.3 0
        500 http://archive.ubuntu.com/ubuntu/ natty-updates/main i386 Packages
        100 /var/lib/dpkg/status
     1:0.150 0
        500 http://archive.ubuntu.com/ubuntu/ natty/main i386 Packages
patrik@ubuntu:~$

##### Output of errors

An unresolvable problem occurred while calculating the upgrade.

Please report this bug against the 'update-manager' package and include the following error message:
'E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

#####

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 1011, in _simulate_helper
    self._get_broken_details(trans))
  File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 1199, in _get_broken_details
    for dep in version.dependencies:
AttributeError: 'NoneType' object has no attribute 'dependencies'
update-manager

#####

Could not initialize the package information

An unresolvable problem occurred while initializing the package information.

Please report this bug against the 'update-manager' package and include the following error message:

'E:Unable to correct problems, you have held broken packages.'

#####

patrik@ubuntu:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
E: Unmet dependencies. Try using -f.
patrik@ubuntu:~$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... failed.
The following packages have unmet dependencies:
E: Unable to correct problems, you have held broken packages.
E: Unable to correct dependencies