Why is Avast giving the warning that some of the antivirus shields are off

Avast Free Antivirus / Premium Security
1

Resolving the problem does not work, the warning keeps coming back after a few seconds.

2

Repair >> https://support.avast.com/en-us/article/Repair-Antivirus

3

If Repair doesn’t fix the problem, try the following:
Clean Install of Avast:
https://goo.gl/4Ptzkf