I am using PS CS6 on a Mac desktop. I have had it installed for a few months now. A few days ago when I used the paintbrush tool it started blinking between the tool and a black arrow making it very difficult to paint. Today it does this with every tool I select. If someone could tell me how to fix this I would appreciate it!!
Does turning off »Use Graphics Processor« in the Performance Preferences and restarting Photoshop have any bearing on the issue?
Are Photoshop and OS fully updated and have you performed the usual trouble-shooting routines (trashing prefs by pressing command-alt-shift/ctrl-alt-shift while starting Photoshop until the appropriate dialog appears after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved and making a note of the Preferences you’ve changed, 3rd party plug-ins deactivation, system maintenance, cleaning caches, font validation, etc.)
Have you installed any accessory software that helps manage the UI in some way?