How to resolve dpkg error while installing Firefox?

Question

I needed to uninstall firefox 19 which was installed during the installation of Ubuntu 12.04, in order to downgrade the version so that I could install firefox add-on compatible to lower versions. But now my system's broken.

I tried to update, or upgrade, apt-get -f install, synaptic installation, or re-install firefox,... but to no avail. Terminal error reports:

sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following package was automatically installed and is no longer required:
  python-zope.app.content
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  firefox firefox-globalmenu
Suggested packages:
  latex-xft-fonts firefox-gnome-support
The following NEW packages will be installed:
  firefox
The following packages will be upgraded:
  firefox-globalmenu
1 upgraded, 1 newly installed, 0 to remove and 9 not upgraded.
1 not fully installed or removed.
Need to get 0 B/25.6 MB of archives.
After this operation, 52.7 MB of additional disk space will be used.
Do you want to continue [Y/n]? y
(Reading database ... 299890 files and directories currently installed.)
Unpacking firefox (from .../firefox_20.0~b1+build2-0ubuntu0.12.04.1~mfn3_i386.deb) ...
dpkg: error processing /var/cache/apt/archives/firefox_20.0~b1+build2-0ubuntu0.12.04.1~mfn3_i386.deb (--unpack):
 trying to overwrite '/usr/lib/firefox/plugins', which is also in package google-talkplugin 3.13.2.0-1
Processing triggers for bamfdaemon ...
Rebuilding /usr/share/applications/bamf.index...
Processing triggers for desktop-file-utils ...
Processing triggers for gnome-menus ...
Processing triggers for man-db ...
Errors were encountered while processing:
 /var/cache/apt/archives/firefox_20.0~b1+build2-0ubuntu0.12.04.1~mfn3_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

How can I fix this?

Answer 1

In most cases, such errors occur when some file was moved from one package to another in a newer version.

This should fix it:

sudo dpkg -i --force-overwrite /var/cache/apt/archives/firefox_20.0~b1+build2-0ubuntu0.12.04.1~mfn3_i386.deb
sudo apt-get install -f

More about this: Fix DPKG Error "Trying to Overwrite X Which Is Also In Package Y" In Ubuntu

Answer 2

Have u tried running this command in terminal:

sudo dpkg --configure -a 

If that doesn't work, try the following because I'm afraid your package was corrupt.

Open terminal and run the following commands:

cd /var/lib/dpkg/updates
sudo rm *
cd /var/cache/apt/archives/
sudo rm *.deb

and try again to install your software.