One or more shields go automatically off

Avast Free Antivirus / Premium Security
1

Hello.
I have found no answer to the following using “search”. Lately -and now nearly every time I turn on the computer one or more of the shields is OFF. I immediately turn the shield(s) ON but when I am finished using the computer, turn it off and on again one or more shields is again OFF. I do not accept this. What do I have to do to solve this?
I use Windows 7 Home Premium and Avast Free Antivirus program version 17.5.2302 (build 17.5.3559.0). Every time I turn on the computer I check for the latest version of Avast Free Antivirus and the latest virus definition.
Many thanks for answer.

2

Repair Avast:

  1. Control Panel → Add/Remove programs → Avast
  2. Click on ‘Repair’.
  3. Follow instructions.
  4. Reboot.
3

There is no need to check for a update if you have automatic check for updates enabled.
avast is already checking at each boot for updates.

4

If the Shield in question is the Behaviour Shield, it’s a known bug and should be fixed by the next version update.