Mac user with PS CC14
Currently when in the Liquify state - zooming in more than 2 stages causes the picture to disappear and is replaced with a checkered grid. Picture will reappear when zoom back out but liquify tool will no longer work. Sometimes the screen will go black and stops responding. Restarting PS or the Mac will no longer rectify the problem.
Up until yesterday I was able to use the Liquify tool for a brief period after restarting my computer.
Do you see the problem on a very small image, say 500 by 500 pixels?