Lightroom panels

When I am in the library mode or the develope mode and click on an image the panels top, bottom and side disappear! It started in the last 24 hrs. I close lightroom and restart and they come back, but disappear when I click on another image!

I minimize light room and bring it back to full-screen I get my panels back. As soon as I click on an image again they disappear.

Now as I type this note, I am clicking and closing and things seem normal again!

Any ideas what might cause this. I have the latest up date of Creative Cloud.

I am on an i mac running Sierra, OS 10.12.3.  It works ok on my laptop.

Thanks

WP