Swank Motion Picture video streams require that the playback devices support Widevine Digital Rights Management (DRM). We have found that many of the Promethean devices do not support Widevine DRM. This can occur when you are using the internal Android chipset on the presentation board.
We can suggest using another device such as a laptop or desktop computer as a streaming source and using the external video input on the Promethean equipment to facilitate playback. This should bypass the internal operating system and use the board simply as a monitor.
If you are using a laptop and the output is still an issue or you are getting an HDCP error, you can change your monitor settings from "mirror" monitors to "extend" monitors, and drag the playback window to the external screen. This should allow playback without error.
For further information we suggest contacting the manufacturer of the equipment.