when I clicked on Synaptic Package Manager from Administrator dropdown

It is showing error like

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

When i typed in the terminal
dpkg --configure -a

It is telling

dpkg: unknown option --configure-a

Type dpkg --help for help about installing and deinstalling packages[*];
Use `dselect' or `aptitude' for user-friendly package management;
Type dpkg -Dhelp for a list of dpkg debug flag values;
Type dpkg --force-help for a list of forcing options;
Type dpkg-deb --help for help about manipulating *.deb files;
Type dpkg --license for copyright license and lack of warranty (GNU GPL)[*].

Options marked[*] produce a lot of output - pipe it through `less' or `more' !

I am not getting head and tail of it...Please help me...

Thanks

run
sudo dpkg --configure -a not
sudo dpkg --configure-a

It sounds like you are either typing it wrong or you were running another application at the same time. You can not have two installer managers running at the exact same time.

Justin

Is the problem solved?