video streaming from Asus router attached hard drive to chromecast

[gow75]

I have an ASUS RT-AC68p wireless router setup as AP mode. the DLNA media server is enabled and the 4tb drive is connected via 3.0 port. the whole drive is shared manually on the asus router. i can get to the drive no problem from my desktop but from my SS galaxy tablet 4 i can not access the folder that has all of my video, pics, movies etc the app that i use on my tablet is EA file manager it says there are no permissions for this folder. i connect the SS to via chromecast on my tv so i want to stream a movie from the SS galaxy to chromecast via storage on my asus. what app is the best to use on the SS galaxy tablet for this? do i need an ASUS app from android?