Hi,
I would suggest you perform a Repair&Update of your Avast, to ensure any minor issues are resolved, please can you follow the steps below:
1. Click on Start > Control Panel > Uninstall a Program (Programs and Features, Add or Remove Programs) > Avast > Click on "Uninstall/Change" > Repair
2. After the repair, please make sure that you have the most recent version of Avast - 2016.11.2.2262.
To do that, please open Avast and go to > SETTINGS > Update > Program > Update and update your Virus definitions as well.
3. Restart your computer.
Please let me know if you are still facing the issue,