All my Color Palettes are MISSING!

I’ve never had this issue before, but suddenly my palettes have all gone MIA. There is not even the default palette that is usually present. I had opened an older file to check it for something, and when I returned to my work, all the color palettes were gone. I don’t even have the option to make a new palette, though I suspect the answer is lurking somewhere. I’ve attached a screenshot of how my color window looks. I hope someone can enlighten me - I had no idea how dependent I was on the convenience of those palettes. Thanks in advance!

Okay, they have returned! I am delighted, but a bit disturbed because I have no idea what I did to make them disappear in the first place, nor what I did to restore them. If anyone has had a similar occurrence, I would be very interested to hear your story. Thanks for the sounding-board.

How did you fix the problem did it just reappear or did you do something else