unblock 3rd party session cookies
I deselected block all cookies, but still cannot open video for school
MacBook Pro 13", macOS 10.14
Try Safari/Preferences/Privacy and uncheck Prevent cross-site tracking. Quit/reopen Safari and test.
Others are seeing the same thing. It seems to be a bug in the newest Safari 13 version.
Block cookies is off but being limited by… - Apple Community
Try another browser until the problem is fixed.
Firefox 10.9 or higher
Opera Browser 10.9 or higher
SeaMonkey 10.9 or higher8
Waterfox 10.8 or higher
You can also try Safari Technology Preview If running Mojave or higher. Go to Safari/Preferences/Advanced and check Show Develop menu in menu bar. Go to the Develop menu and select Get Safari Technology Preview. Open from the Applications folder.