Photoshop CC (2014) crashes when you quit. You were working with Styles, Brushes, Patterns, or Tool presets.
This issue is under investigation. Use the workarounds below until a solution is released.
It's best to save your presets in the default locations:
After a fix is released for this issue, return to Preset Manager, select Load, and select your saved presets.
If previously used presets contain this issue, syncing them can reenable the issue.
After a fix is released, reselect Brushes, Patterns, Styles, and Tool Presets in Sync Settings.
After performing the steps above, don't migrate your settings from earlier versions, as it can reintroduce the presets that trigger this issue.
If you still run into repeated crashes when quitting the application after doing the above steps, post the crash log to the User To User forum (forums.adobe.com > Photoshop) under a title, 'OSX Crash on quit: mutex_lock'.