I have been using Paperpile for a while and enjoying its features. However, today, when I press "view pdf" on a paper in my paperpile, it's just chromes normal pdf viewer.
There is a similar topic on the forum in the past, however, the chrome browser has changed since it was answered. I went to the equivalent of chrome plugins (more tools -> extensions) and it does not list a chrome default pdf viewer to turn on or off. I'm unsure why this is not working.