A pop-up blocker is a feature that prevents pop-ups from displaying in a user's Web browser. Pop-up blockers work in a number of ways: some close the window before it appears, and some disable the command that calls the pop-up. 

Most of the courses you launch are opened in a new pop-up window. By disabling the Pop-up Blocker, the pop-up window will be able to load the course content successfully so you can take your training.