Gallery quit working after Kitkat. I can no longer see any thumbnails unless I remove battery and reinstall. Then it quits again and I have to remove battery again. Plus I cannot OPEN any pics stored on the sd card using Gallery at all any longer. I can see everything using Google's Photos app but of course it's not sorted at all and the thumbnails take several minutes to load. It was all working great before Kitkat .
Being able to view your pictures is very important! Lets get you access to those photos. Have you tried to remove your SD card and see if you can view the photos in the gallery? Are you able to view other information that is stored on the SD card? If you go to Settings>Storage does is show the Note 3 recognizes the SD card?