Some users may have trouble streaming/viewing class videos. This may be a simple issue with your web browser. Try loading the video on different web browsers, for example, Chrome/ Firefox/ Safari, etc.
This is a step process to follow until the issue is resolved so do them one at a time. Most are resolved within the first one or two steps thankfully:
If you continue to experience problems, please contact our dedicated Customer Support Team at "support@upskillist.com" with device information like the version of the Web browser along with Operating System details.