Troubleshooting Video Playback Problems


If you experience any of the following occurrences when playing videos, for numerous videos on the site:

  1. A "Sorry, clip not found. Media not found" error message within the video player
  2. A black box where the video player would normally appear
  3. An empty area where the video player would normally appear
  4. A grayed-out play button on the video player and not seeing the videos play
  5. A constant spindle in the center of the video player prior to the video playing
  6. "An error was experienced when playing the video. Please check your internet connection and try again"

Then this is likely due to one of reasons listed below.

  1. The computer, or device, which is accessing the videos not having Adobe Flash Player installed.
  2. The local computer's, or local network's, web filter blocking content originating from the Akamai Content Delivery Network (CDN) which is the source of our video stream.

Note: If you are experiencing symptoms that are different from those listed above, please contact Technical Support via the Contact Us tab at the top of this page.

Otherwise, we recommend that you first try using any or all of the following solutions to address your issue. The “Update Flash Version” section addresses the Adobe Flash Player application not being installed. The “General Whitelisting”, “Whitelisting for Kaspersky Anti-Virus”, and “Whitelisting for OpenDNS”sections address the installed web filter not properly filtering the videos from the source.


A. Update Flash Version

You will also need to verify that you have the latest version of Adobe Flash Player running on your computer. You can download the latest version of Adobe Flash Player by using the following information:

  1. Access the webpage
  2. Click on the "Downloads" tab
  3. Click on the "Get Adobe Flash Player" link
  4. Download and install the latest version of Adobe Flash Player.
  5. Restart your computer and access the content once again.

B. General Whitelisting

The issue you are experiencing is due to the web filter of either your local computer's network or school network not properly filtering videos originating from the Kaltura Content Delivery Network (CDN) which currently streams the videos.

If you are accessing the platform from on-campus, then please inform your institution's IT department to please white list (create an exception rule) in your institution's DNS filter, web filter, or Anti-Virus web filter for the following domains from which the videos will be streaming and this will alleviate the issue.

If you are accessing the platform from off-campus, then you will also need to white list (create an exception rule) on your home network's (local computer) DNS filter, web filter, or Anti-Virus web filter for the following domains:

C. Whitelisting for Kaspersky Anti-Virus

If you are using any version of Kaspersky Anti-Virus (especially "Kaspersky Endpoint Security 10"), either on your local computer or deployed through your institution's network settings, then you will need to add the following Kaltura streaming URLs to the list of trusted URLs:

The Web Anti-Virus feature, within Kaspersky Anti-Virus, is blocking content coming from the Kaltura streaming URLs because it is incorrectly labeling them as containing potentially dangerous scripts within the associating web pages. Web Anti-Virus protects the data incoming to and outgoing from a local host over HTTP and FTP, and detects links leading to suspicious or phishing web addresses.

Please use the following steps to update the Web Anti-Virus feature so that the Kaltura streaming domains are listed as trusted URLs:

  1. Edit the Policy for the Kaspersky Anti-Virus software
  2. Under Anti-Virus Protection, select <Web Anti-Virus>
  3. In the Security Level box, of Web Anti-Virus, select <Settings>
  4. On the <Trusted URLs> tab enter these URLs:

D. Whitelisting for OpenDNS

If your institution's, or individual home network's, local DNS server points to the OpenDNS servers for domain name resolution and content filtering, then your IT department (or yourself) will need to make some adjustments to the Kaltura streaming domains that need to be white listed within OpenDNS.

The Kaltura domains ("", "", "", "", "", ""), which is where the video player and videos are originating from, is currently categorized as a "video sharing" domain on the OpenDNS list of domains. Within OpenDNS, If the "video sharing" category is one of the categories of domains which your institution has listed as blocked domains then the On-Demand videos will be blocked from being able to stream through your local network as a result.

Your institution's IT department will need to manually white list the Kaltura domains ("", "", "", "", "", "") within OpenDNS, so that the On-Demand videos can properly stream through your local network.

E. Advanced Troubleshooting Steps

If you are experiencing an issue while trying to play the videos that is not addressed in any of the above instructions, please provide us with the following information so that we can further assist with troubleshooting:

  1. A detailed step by step description on how to reproduce the issue, including example pages and credentials (if any are required) so that we may reproduce the issue on our end.
  2. Traffic logs captured while reproducing the issue. In order to capture web traffic that can help us diagnose the issue, please follow the instructions in the following article using the corresponding link:

You can submit this information to our Technical Support department via the "Contact Us" tab, found in the menu bar towards the top of this page.

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