Why do Exit Actions to URLs fail to trigger when target frame is set to 'this window'?

Why do Exit Actions to URLs fail to trigger when the target frame is set to 'this window'?

A: When the Exit Action to URLs target window is set to 'this window' the exit action will not trigger. This causes the webpage to produce a scripting error within Developer tools that causes the screen to display all-white for presenters & attendees. When the target window is set to 'new window' the exit action triggers, and the URL is launched within a new window. Ensure that all pop-up blockers are disabled.

Screenshot of Development Tools script error