If you use Photoshop CC on a Mac and it crashes when using GPU-assisted features like Smart Sharpen, you may need to turn off OpenCL support in Photoshop until the problem is fixed. Reports point to a possible bug in the Apple graphics driver for AMD/ATI GPUs in OS X 10.9.2 Mavericks. (Which means this crash may only apply to you if your Mac has that type of GPU in that version of OS X.)
[Update: This did turn out to be an Apple bug. Apple fixed it in OS X 10.9.3. If you are running 10.9.3 or later you do not need to perform the steps listed below; you can leave OpenCL turned on in Photoshop. This also means that if Photoshop is crashing and you are using OS X 10.9.3 or later, the cause is probably not related to this problem.]
The official Adobe help page for this issue walks you through the steps to disable OpenCL support in Photoshop:
For some time now, Adobe has been advising customers that some Photoshop CS5 crashes were traced to bugs in the font code in Mac OS X. It appears that Apple has now fixed many of those crashes in today’s release of the Mac OS X 10.6.5 update, according to Photoshop engineer Chris Cox in a post at the Adobe support forums.
If you’ve experienced these crashes (I haven’t), download Mac OS X 10.6.5 and you’ll hopefully see an improvement in Photoshop stability. As always, I recommend downloading the Combo updater if you’ve got the bandwidth for it.
On a side note, if you’ve got a new camera and you’ve been waiting for Mac OS X to support its raw format, check the list of camera raw formats added in 10.6.5. It contains new support for some notable recent models such as the Canon PowerShot S95, Canon EOS 60D, and the Panasonic Lumix DMC-LX5.
If you experienced crashes in Adobe Photoshop CS5 on the Mac after installing the Mac OS X 10.6.4 update, there were issues with the graphics drivers in that particular Apple update that may have caused your crashes. (The bugs may have also affected you if you use Apple Aperture or play certain graphics-intensive games under Mac OS X 10.6.4.)
If you had been holding at Mac OS X 10.6.3 like I’ve been, it looks like it’s finally safe for Photoshop users to move up to Mac OS X 10.6.4 as long as you also install Snow Leopard Graphics Update 1.0.