I had to deactivate the Emergency Update in Windows’ schedules tasks, because for the past two or three versions of the program, everytime an Emergency Update takes place, I have to completely re-install Avast as the User Interface no longer responds (i.e., right-clicking the icon and selecting any task does nothing, and double-clicking the shortcut doesn’t bring the UI up, either).
A repair of the program doesn’t fix the issue. You simply no longer can use the program and are forced to re-install it.