Sometimes your Adobe After Effects window gets stuck off screen. I tried everything:

  • Changing Display
  • Changing Zoom
  • Unplugging Monitor
  • Rebooting

It was still there! Then I found @uedvincent‘s advice on and voila!

TLDR Solution and Video Demonstration

Put mouse on the edge of the window
Hold the Option Key and while holding DOUBLE CLICK on the mouse!
Video demonstrating this: