Avast program won't start after being installed

I just installed Avast and have the icon pinned to the task bar. When I click on it - it opens the avast dashbord but when I try to run a scan it just shuts back down.
Please help!
Thanks

Do you (or did you) have any other security software installed? If so, which one(s) ?
Have you rebooted and tried again?
What os?
What version of avast?

“Have you rebooted”?
Yes there are users reporting more then one boot required after installing.
Sometimes the Drivers are stubborn. :wink: