Gallery and Camera freezing on Samsung Galaxy Note 4 Kitkat and Lollipop. I have experienced this with two different new Note 4 s. The problem was caused by my Dropbox Cloud Settings.
Solution: Go to Settings > Cloud . Scroll down to Dropbox. Turn off sync for Pictures and Video. When these settings are enabled you should be able to see your Pictures and Videos in Gallery, however in my case this was clearly too much for Gallery to handle.
Clearly this should be able to be linked but in my case it Crashed Gallery and my Camera.
Solution: Go to Settings > Cloud . Scroll down to Dropbox. Turn off sync for Pictures and Video. When these settings are enabled you should be able to see your Pictures and Videos in Gallery, however in my case this was clearly too much for Gallery to handle.
Clearly this should be able to be linked but in my case it Crashed Gallery and my Camera.