The JavaScript exception "Permission denied to access property" occurs when there was an attempt to access an object for which you have no permission.
DOMException: Blocked a frame with origin "x" from accessing a cross-origin frame. (Chromium-based) DOMException: Permission denied to access property "x" on cross-origin object (Firefox) SecurityError: Blocked a frame with origin "x" from accessing a cross-origin frame. Protocols, domains, and ports must match. (Safari)
There was attempt to access an object for which you have no permission. This is likely an <iframe> element loaded from a different domain for which you violated the same-origin policy.
<iframe id="myframe" src="http://www1.w3c-test.org/common/blank.html"></iframe>console.log(frames[0].document);
// Error: Permission denied to access property "document"