I was going to upgrade from 12.04 to 12.10 and skipped the update for libmagickcore4-extra, and some problem occurred, and the upgrade stopped. Now, whenever I try and open the Software update, I get this message:
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:The package libmagickcore4-extra needs to be reinstalled, but I can't find an archive for it'
I tried finding a solution on How do I resolve unmet dependencies after adding a PPA? but with no luck.
The terminal gives the same error message.