The computer and internet environment is a rather unstable place. There are so many variables in play when accessing a course online, including one's internet connection, computer, operating system and browser, as well as any add-ons or plug-ins that may be enabled in those browsers. As of this writing, we have identified difficulties that seem to be related to Mac computers running Safari browser, Internet Explorer 10 browser, and Windows 8 machines running Internet Explorer. As the first step to troubleshooting, try running Google Chrome on either machine - it has proven to be very stable in most environments.
If this does not solve your issue, please submit a helpdesk ticket and we will address your specific issue.