I have the free Avast for Mac. I am on High Sierra. Today, for the first time, every time I try to open Avast it pops up saying I'm protected but immediately something else covers most of it and says "Help us keep you safe. Your mac is not covered by real time protection. Systems software from developer "Avast Software a.s." was blocked from loading. Asks me to allow it to use real time protection. Most of the text is orange and black. It wants me to go to Security and Privacy to change my settings. There is an orange rectangular box that says "Go to system preferences" . At the very bottom in small print I could clink on to continue without real time protection (not advised).
I am very leary to click on this til I know it is legit (was once burned by something else). Thanks for any help.