social video

Dear Sir, madam, I try to add a hyperlink for a video to the site of easysocial, but I receive an error, when I add the hyperink directly in the browser, it is working. see attachment. Joomla 3.65, php 5.6.25, db 5.7.14. further more I cannot find the location of path to ffmpeg, I put the folder in several directories. path is r/w rights. I hope you can help me? the site is only internal available not for the web. Video's from you tube are no problem.
best regards Ton