Virus Definitions Update Unsuccessful

Have never had a problem in the past updating virus definitions. Today, I received the red warning that they were unable to update them (have tried updating three times). Here is the message I keep receiving:

“Last encountered error - the package is broken”.

Would appreciate any information as to what this means, and how should I proceed
Thanks for any help.

Please see comments from igor here → http://forum.avast.com/index.php?topic=99036.0

Thanks so much for your reply - appreciated your assistance. Great work!