I have upgraded from Lightroom 5 to Lightroom 6. Download and install seems to have been successful (after 4 tries.) However, in Lightroom 6 after importing a photo, when I go to the "Develop" pane, all I see is a blue panel with an X through it; not the photo I am intending to edit. Can anyone explain this to me? I have been using Lightroom 5 successfully for a year and never encountered this problem.
2 links that MAY help (or may not, I'm not sure)
-Lightroom Version 6 http://www.lightroomqueen.com/lightroom-cc6-myths-confusion/
Edit >> Preferences >> Performance
Lightroom >> Preferences >> Performance (on Mac OSX)
Then disable GPU acceleration.
For Windows you should go to the website of the manufacturer of your graphics processor and check for driver updates. After updating you could try switching GPU acceleration on again, otherwise leave it disabled.
On mac GPU updates happen with OS updates.