First Rule of tech support is of course is it on? One of the most common things is the power to the display or media player is not on. Perhaps someone used the remote and turned it off or accidentally changed the input and it is no longer on the HDMI input.
If after checking and verifying that the display and media player are both turned on yet still nothing is displayed please email support@cannabisclub.tv or call 855-763-2288 and we will help you as soon as we can.