Virus definitions and program update is stuck at "Initializing, please wait..."

For the past 4 months or so, I have been unable to update the virus definitions or Avast itself. I press update and it gets stuck on “Initializing, please wait…” and the progress bar remains completely grayed out.

What can I do to resolve this issue? Thanks!

Have you tried a repair :-\ next step if that fails would be a clean install.