The Samsung VR mobile app com.samsung.android.video360 can't play videos in VR mode after this week Oculus update.
It pops the massage "Insert into Gear VR", but that just brings up the Oculus Home, not the video.
That app was the only sensible way to to play videos, as it supports DLNA server.
i7 3970x @ 4.4GHz | 64gb ddr3 | MSI GTX 1060 6GB | Gigabyte x79 UD5 | Samsung NVMe 960 pro | 10 x 3TB WD green
Gear VR Innovators Edition | Note 3 | Note 4