When your Avast antivirus is unable to scan files, follow the instructions below to fix it:

• On your computer, go to add or remove programs and look for Avast.
• Right click on the file and select the ‘repair’ option.
• Now, restart your computer and open Avast and click on the ‘fix now’ button to fix any error or problem in the program.

If this method does not work for you then you should contact how to contact avast customer service to get a professional’s help to fix your problem.