Have Samsung Galaxy Tab 3. All of a sudden when I send photo to dropbox to upload doesn't work. I check dropbox and have the message "waiting to upload", but never loads.
Make sure you are using latest version of Dropbox app.
Try to clean Dropbox app data and cache using Application Manager, to do so go to:
Settings > Application manager > Dropboxhit
Clear data & Clear cachethis will clear your account information and cached data stored on your device. After this just log in to Dropbox with your account once again and it should work.