Those of you who have this error:
1. In Android Settings, go to Apps. Select Dropbox.
2. Click "Force Stop".
3. Click "Permissions".
4. Click on "Photos and Videos".
5. Select "Don't Allow".
6. Restart Dropbox. Open Dropbox Settings.
7. Click on Camera Uploads.
8. Dropbox will ask you for permission again. Select "Allow All".
9. Done. It's fixed.