If you are experiencing issues, please read and follow the instructions below depending on the browser you're using:
For Firefox: on the top bar, select the button at the far right (three horizontal lines), click on the question mark at the bottom and then select "About Firefox" (last option on the list). Firefox will check if it's up to date. Then, please go to this webpage: http://www.mozilla.org/en-US/plugincheck/ There you can update the relevant plugins for your browser, which are critical.
For Chrome: At the far right end of the browser, click on the icon with horizontal lines and click on About Chrome. If the browser is not up to date, please download the latest version.
For Safari: Please make sure you have the latest version, and if not, download it from http://www.apple.com/support/mac-apps/safari/
We do not recommend using Internet Explorer for viewing the courses.