Symptoms
When you open the F12 Developer Tools window on a webpage that contains a nested IFRAME and the WebBrowser-ActiveX object, the webpage contains with an access violation. The access violation also occurs if you have F12 Developer Tools open and you move to a webpage that contains nested IFRAMES and on which the WebBrowser-ActiveX object is loaded.
Resolution
To fix this issue, install the most recent cumulative security update for Internet Explorer. To do this, go to Microsoft Update. Additionally, see the technical information about the most recent cumulative security update for Internet Explorer. Note This update was first included in the MS16-023: Security update for Internet Explorer: March 8, 2016.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.