I've yet see Samsung step up on this one. That is, they do call out what should work but never commit to "this will work."

I must do the same since I have no idea how you prepared the HDD or if the content is compatible or there is a hardware issue.

http://www.samsung.com/au/consumer/tv-audio-video/television/archive/UA40ES5500MXXY seems to find 2 things.

1. It mentions USB as in a stick. That's odd.
2. There's a 2016 firmware update. Ask Samsung if it applies to your model and how to install.