I upgraded my Windows 8 home computer to Windows 10 and now all LR thumbnails are blank as well as the Navigator image. I can't find any solution online for this. Some were posted but they didn't work for me. I upgraded to the latest LR and upgraded to the latest GeForce graphics driver for my system. I have tried LR with GP support and without.
Good first step done- update graphics driver,
Here is two more possibilities-
1. The monitor profile installed with Win-10 does not suit Lr. http://www.lightroomqueen.com/articles-page/how-do-i-change-my-monitor-profile-to-check-wh ether-its-corrupted/
2. The Catalog Previews.lrdata file is corrupt. Re-name it, or delete it, and let Lr re-build the previews.
thanks for the rapid and correct response - I didn't have a color profile associated with my monitor.