I have Photoshop CC 2014 and after I've updated it (a few days ago) I'm now unable to use certain blending modes. I can use 'Normal', 'Dissolve', 'Darken' 'Multiply' and 'Screen' but nothing else. The others are un-clickable. Does anyone know what I've done and can they tell me how to fix it?
Sometimes corrupt preferences can be a common cause.
If you need a quick and dirty way to restore your preferences, here's a way you can do it using a keyboard shortcut on launch:
Windows - CTRL-SHIFT-ALT immediately after you double-click the PS icon.
Macintosh - CMD-SHIFT-OPTION immediately after you double-click the PS icon.