Warning Messages

Having used Avast for a few months now I’m very pleased with it but as a newbie to this forum I have a few questions.
I have messages flashed up that there are unsafe plug-ins etc or other problems with the browsers. However when following up the details nothing is shown as a problem and everything listed as OK. Why? This message appears seemingly at random.
Is it possible to view start-up programs and/or services that Avast indicates should be removed? There seems to be no way to determine what is referred to and I’m reluctant to have things removed or changed without knowing what they are.
Related maybe to the first question but a different warning: I have a plug-in that I have used for years, regularly updating, that is constantly flagged as a dangerous plug-in. It is not. How can I stop this message coming up every time I open the browser?
I regularly scan for problems etc and no other security program show similar warnings

There have been numerous comments along the same lines.
You may find better answers in this forum.