Sometimes, when I turn on/off notifications on a post in my news feed while running the Avast Online Security extension for Chrome, Chrome and Facebook seem to think the Facebook dropdown menu is still open even after I close it. This ends up making it so that I can't scroll through my news feed using the up and down arrow keys or the space key because they are all interpreted as inputs to the Facebook dropdown menu. I've asked Facebook for help with this, but they say it's the extension's fault.