First, check to make sure that you have a good internet connection. You can visit https://fast.com, a service provided by Netflix, to test your connection.
If you connection is strong, there are a few other reasons your course isn't playing, that includes:
Old Web Browser: Older web browsers such as Internet Explorer 11 typically take a long time to load the videos. Try a different browser, that is likely already installed on your computer, like Chrome or Firefox.
VPN and/or 3rd Party File Management Software: Log out of your VPN ("Virtual Private Network") and/or 3rd party file management software (such as TrialWorks). Connecting through these channels has been known to cause issues with the LexVid video player.
Ad Blocking Software: This may prevent the video from loading. Try turning off the ad blocker or adding LexVid.com to the list of approved sites.
Work Firewall: If you are at work, your firewall may be blocking the video. If so, you can either log into your account at home or through your moblie device, or check with your employer's IT specialist about allowing LexVid through the firewall.