
Secondly, if that doesn't work, (just if it doesn't work, if it work, there's no need to do that) try reinstalling your Avast, if it's some bug in the settings or something in your avast, that shall redefine everything and fix it. So, first, update your AV, any bugs will be patched after that and the newer updates doesn't allow more than one warning per moment, it just packs everything into one warning, so it shall relive the discomfort if it keeps happening.

Sorry for the late response, try updating your Avast, it may be some bug related to the web shield or some hacker attempting to hack into your machine, to encrypt files, steal things, destroy it, etc, targeting you or maybe the websites you visit, I wouldn't advise you to disable the Web Shield unless as last measure.
