Try clearing your preferences to defaults by pressing and holding Command - Shift - Option immediately upon cold-starting Photoshop. If you get the keys down quickly enough, it will prompt you to confirm deletion of your current preferences.
Thank you. I was unable to get that prompt to come up.
I did however, go into my preferences and drag the Photoshop CS6 settings to the desktop. Restarted Photoshop and it appears the issue has resolved.
You're welcome. Glad to hear that clearing the preferences got things working again.