Sequencer says it is open, but isn't shown on screen

As you can see from this image, Sequencer says it is open, but is nowhere to be found. It is not on a separate monitor, and is not in another tab or anything. I click open level sequencer and nothing happens. I have no idea what is going on.

In the drop-down menu at the bottom choose Load layout > Defaut Editor Layout.
This will reset the layout and display your window again. This fix worked for me!