I have a yellow triangle/caution sign next to one of my lessons and cannot continue.

1. Click on the yellow icon.  Another window will popup; close the window. 

2. Delete your temporary Internet Files (click on - Tools - Internet Options and under the "General" tab select Delete under the Browsing History option. JUST DELETE TEMPORARY INTERNET FILES

3. Logout and log back in to PTS University.  You will then be able to launch the course normally.