Somedays I will be working in Photoshop and suddenly, certain features will cease to fucntion. It happens with pretty much everything from selecting brushes to creating a layer mask to creating an exposure layer. VERY occasionally, this will be accompanied by the program hanging or even quitting out.
The features are re-enabled once I restart but once it has happened, I have to reboot my computer to make sure it doesn't recur again that day.
I have noticed that it happens mainly on very busy days so I am wondering if there is some sort of cache that might be filling up and a preference which could prevent this - but I dont know.
When Photoshop crashes, this is the first thing to do, try resetting your Photoshop preferences. Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) immediately after launching Photoshop. You will be prompted to delete the current settings. You can also reset preferences upon a quit if Photoshop is running by going into General Preferences>General>Reset on Quit.
Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"