I have 5.0.418 version Avast free. If I click on the show last pop-up (alert) button I cant click on the notify file like false detection. This title isnt active why? 
Because that is just the pop-up in isolation from the alert, there is no connection to the original detection.
despite all the button should work at
Sorry I don’t understand what it is you ask as it looks like you didn’t finish the question.
avast has in the bast left options that can’t be selected/used greyed out, like the boot-time scan option in 64bit OSes, so the the users knows that option isn’t available.