KBA-009 - LabSim Course Content Not Loading

KBA-009 - LabSim Course Content Not Loading


When a LabSim section is launched - be this an exam, lab simulation, or other section within the course - content does not load. Usually the section will partially load, but either the 'Loading' indicator never completes, or images do not appear on lab benches, or related.


There are multiple possible causes for this type of problem with the Labs.  Each of the following troubleshooting steps should be followed in order: 

  • For LabSim courses which use Microsoft Silverlight: The computer is running an older version of Microsoft Silverlight.  Go to www.microsoft.com/getsilverlight and install any Silverlight updates that are available.
  • The Microsoft Silverlight plugin may be damaged. Uninstall Microsoft Silverlight by going to Control Panel > Programs ([to] Uninstall a program).  After Silverlight has been uninstalled, reinstall it from www.microsoft.com/getsilverlight   
  • A non-default Regional/Language setting has been set on the user's computer.  Set the Regional Language Format to English (United States).  On Windows XP or Vista go to Control Panel, Regional and Language Options, and click on the drop down box to change the Format.  On Windows 7 go to Control Panel, 'Clock, Language, and Region', click Region and Language, and change the Format in the drop down box.
  • Security settings in Internet Explorer can prevent sections from loading correctly. To fix this, add cdn.testout.com and *.testout.com to trusted sites in Internet Explorer. You can also try using another supported browser for your course. (See the list off supported browsers for your course in the My Product list on your LabSim home page)
  • A software or hardware firewall may be stopping the associated course exam files from downloading and loading on the computer. This issue is generally overcome within the firewall by allowing traffic from the following TestOut server resources:
    • Cdn.Testout.com
    • Testout.com: 
  • In some more rare cases it has been noted that certain security aware SOHO routers have blocked course exam files from downloading to the computer. This issue has been remedied by connecting the computer to the router and/or modem via Ethernet cable, thus bypassing what may otherwise be a Wi-Fi connection to the same device (be sure to disable your Wi-Fi antenna on your computer when doing this test). The issue has also been overcome by entering the IP address of TestOut's load balancing server within the DMZ of the router device. This IP address is, which resolves to content.testout.com. On Cisco and Linksys routers this issue has been resolved by disabling Intrusion Detection System (IPS). This is enabled by default.
  • Blue Coat - K9 Web Protection has blocked random LabSim course content files.
  • Sometimes security or other software can interfere with LabSim. The easiest way to make sure nothing is interfering is to do a clean boot with msconfig (Boot to Safe Mode with Networking). For instructions see this link: http://support.microsoft.com/kb/929135

If issues persist, or if additional information is needed, please contact Technical Support via any of the below options:
Telephone: 800-877-4889, Option 5
Email: support@testout.com
Live Chat: See link upper right at http://www.testout.com