This keeps popping up. Should I press "Don't Allow" or "Okay"?

This keeps popping up on my screen. I tried looking for "420402216190876546" in finder and spotlight search but it doesn't show up for anything. I have been pressing "Don't Allow" because I don't want to mess anything up. But this keeps popping up every 2 min or so and it is getting really annoying. This little box that has nothing in it always pops up with it and disappears with it too. Here is the screenshot.