Mediasite: Slide Feed Showing “Black Screen” in Safari

Overview

If you are viewing a dual-video Mediasite presentation (presenter video + slide feed) in Safari and see a black screen where the slides should appear, you are experiencing a known Safari playback issue.

This issue is usually caused by strict browser privacy settings, specifically blocked third-party cookies or the "Prevent cross-site tracking" feature. Other common causes include outdated cache, high-bandwidth demand, or content protection (HDCP) mechanisms on newer Mac laptops.

The most effective and reliable solution is to simply open the presentation in a different web browser.

 

Symptoms

You may notice the following behaviors specific to Safari and its playback settings.

  • The presenter video plays, but the slides are black.
  • When scrubbing along the timeline, you can see thumbnails of the slides, but they don't display onscreen.
  • Sometimes both videos load, other times only one loads.
  • Refreshing the browser window does not consistently fix the issue.

 

Recommended Solution (Best & Fastest Fix)

Step 1: Open a new Internet Browser
If you do not already have one installed, download and install Mozilla Firefox, Google Chrome, or Microsoft Edge on your device.

Step 2: Copy the Mediasite Link
Highlight the full presentation URL in Safari’s address bar. Right-click and select "Copy" (or press ⌘ + C).

Step 3: Paste the link into the new Internet Browser
1.    Open a new Mozilla Firefox, Google Chrome, or Microsoft Edge browser window.
2.    Paste the presentation URL into the address bar (⌘+ V).
3.    Press "Enter". Your slides should now display normally when you play back the Mediasite presentation.

 

Verification / Expected Result

After opening the Mediasite presentation in Mozilla Firefox, Google Chrome, or Microsoft Edge:

  • Both the presenter video and slide feed load.
  • Slides advance normally.
  • No black screen appears in the slide area.

 

When to Contact Support

Please open a "Report Mediasite Issue" ticket with us if:

  • The presentation does not load in any browser.
  • You receive an access or login error.
  • The video fails to play entirely.

Please be sure to include the following in the ticket:

  • The presentation link
  • The lecture or event title
  • The browser you are using
  • The version number of the browser you're using. If you're not sure how to do this, please refer to the appropriate directions below:
    • Find your Mozilla Firefox browser version: Click the icon in the top-right of the browser window Help About Firefox
    • Find your Google Chrome browser version: Click the icon in the top-right of the browser window Help About Google Chrome
    • Find your Microsoft Edge browser version: Click the icon in the top-right of the browser window Help and feedback About Microsoft Edge