Please add Sniffer.exe & Photoshop.exe under the Nvidia Control for the High Performance.
Files Location: C:\Program Files\Adobe\Adobe Photoshop CC 2015.5
Check the step by step instruction on the below link.
Here are some of Tips ..
one of the Reason that Could Cause that is The Graphic Card Driver ,, check for Update.
you can Uncheck the GPU Check Box
Restart your PC/MAC/ Laptop
Recheck it Back on
One more Tip : i used to Do it All the time and it works :
Reset Photoshop Preferences File. its Easy to Do
Edit -> preferences -> General
Reset Preferences On Quit.
Quit Photoshop and Re-launch it again
you can Also Check this Adobe Link for More Help
sniffer.exe and photoshop.exe are both in the nVidia settings, set to use the GPU. I also have it set to default to the GPU for everything. I've tried resetting the preferences, to no avail.
What I did discover is that if I have the GPU checkbox unchecked and open an image, I can then go in and check that box and everything works fine. But if it's checked before I open a file, I get the error originally documented here.
I have a similar problem. It seems the GPU gets "undetected" as soon as I open a new (or existing) document.
The fix presented here doesn't work.
uninstalling and reinstalling seems to work for now
aaaand it's still broken.
I Have exactly the same problem in my laptop. Until previous version no problem at all, but from 2015.5 version similar problem occurs. GPU vanishes in preferences after opening an image. I have Nvidia GeForce GT420M gpu, intel i5, 4gb ram, dell xps 15 (year 2010).
Your workaround is so far the only thing that worked for me, ie., turning off GPU acceleration prior to opening the image and then turning it on prior to using the Liquify tool. Once you do this you can use the Liquify tool as many times as you like.
Adobe support tried uninstalling and reinstalling. I do not recommend this since all that this did was crash my system and when I got it back I had to reload all of my brushes, actions, gradients, etc., only to find the same error still present. I hate being a conscripted beta tester for every version of Photoshop CC that has come out. Thanks