If you are streaming a video course and you can only hear the audio portion (audio only, no video), the most common reason is a poor/slow internet connection. Our streaming provider uses adaptive streaming technology and if the system detects that you have a slow connection and doesn't have enough bandwidth to stream both the video and audio portions of the course it can down sample the stream to audio only.
The way to fix this is to check your WiFi and move to a better location or different network as needed. This could include resetting your internet modem and WiFi (if different) (unplug it for 30 seconds and plug it back in). Also try rebooting your mobile device.
If you continue to have issues with streaming our courses please contact us so that we can assist you further.