Dropbox links only work over SSL

Thanks for the report. The servers for dl.dropboxusercontent.com are not currently listening on port 80, meaning that http:// requests won't work. We're looking into whether or not we can re-enable that, but for the sake of security we highly recommend switching to using https:// only.

In the Android Core SDK media function, this means passing true as the ssl parameter.

For reference, in the interest of user security, we stopped serving content over http a long time ago, and redirected requests from http to https after that, so it is likely that any clients you're using are already able to handle https links.