Hey there,

I am really sorry for the delay of this reply as it is a weekend for us here.

It shouldn't affect this if using subdomain site, but you can check this following thing and see if it help with this issue :

1. Ensure that you have setup FFmpeg on your server. (version 2.8.x)

2. Ensure you have enable 'passthru' PHP function from php.ini (make sure do not put this 'passthru' under disabled_function php directive)

3. Ensure the ffmpeg binary path set correctly from the backend > Easysocial > setting > videos (you can check this location from your SSH , type this command whereis ffmpeg)

4. If you got setup open_basedir path from your php.ini, you have to set this ffmpeg binary path as well.
If this open_basedir is empty, you can ignore this checking.

If the issue still persists, can you update your development site backend and FTP access at your first post so we can better have a check?