GeorgefromLightbox:
So, I think the original issue (that 3rd party/imported Android TV boxes are rooted and therefore the DRM doesn't work) still stands, as the reason is broadly the same: those ROMs don't support the right DRM format.
That said, the fact your rooted HTC One still plays content must be perhaps because it has suitable DRM support - and I'd guess this is perhaps through Widevine Modular which, for ref, is what our Android app player SDK supports (via CastLabs) uses.
Indeed, DRM info on my HTC shows:
I think the root status is a bit of a red herring - Lightbox will work on a rooted box, but the boxes in question being cheap and basic lack the required DRM support (get what you pay for!), hence my point about more informative error messages or some kind of warning.