cant open synaptic manager and software centre

and one more thing, am not running any applications...

You should check that you're running the package manager with root privalidges and that no other package managers are running.

If you're sure of the above then use '$ sudo dpkg --configure -a'.

If that doesn't work then paste the output of '$ lsof | grep /var/lib/dpkg' for us to see which processes have handles on the locked file.

i tried first command, when i run the second command, it didnt show any output....
now am facing another problem....

it is displaying like
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
E: _cache->open() failed, please report.

The solution to that error is in my previous post, '$ sudo dpkg --configure -a'.

Once you've done the above command, please try installing a package and paste any errors.

i tried that command...it is displaying same error

E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
E: _cache->open() failed, please report.

You've checked that no package managers are open (Synaptic, Update Manager, apt-get etc.) and restarted before doing the command?

Please reboot before doing command.

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