Error in downloading the gigantic files from dropbox website? You are not alone! (https://www.dropboxforum.com/t5/Installation-and-desktop-app/download-large-file-using-browser-fails-before-end/td-p/144419)

Here is my solution:
1. Use a download manager such as Turbo Download Manager (it has chrome/firefox extension: https://add0n.com/turbo-download-manager.html).
2. Download the file using this download manager.
3. When the download pauses (likely the connection is closed), refresh the dropbox download page and try to download again.
4. When the new download starts, look up the mirror download link for this new download. Now you can cancel this new download.
5. Update the mirror link for the old download. The old download can now be resumed from where it failed.
6. If it fails again, repeat step 3~5.

Good luck!