In the answer on Which browsers are officially supported, and what else do I need? a link is offered to the Network Login Help page.
I'm not sure if that page is still relevant given the changes introduced when Universal login went live but given that the test page has not yet been deprecated I like to report a bug with the test on that page for Messaging. This is my current result:
Followed at the end with the epic Houston, We Have a Problem.
I do assume Chrome 59 and Edge are browser that are modern so it doesn't seem to be caused by my local setup.
Instead of what Apollo 13 did by flying around the moon I suggest you make a slight adjustment in the JavaScript that is in test-globalauth.js:
On line 38 you have this line:
if (evt.origin.replace(/^http:\/\/([^:\/]*).*$/, "$1") != document.domain)
That regex doesn't handle the fact that you're now on https because I if run what that test is supposed to do in a console:
window.addEventListener("message", (e)=>{ console.log(e) });
window.postMessage("I am a message",window.location.href);
it works as expected.
Can you make the necessary changes to that regex so the Messaging test succeeds again?
String.prototype.replace...), the tests will still fail because the code inside the iframe (loaded from stackauth.com/login-test) also has a hardcodedhttp:protocol prefix in the.postMessage()call used to relay the test results back to the surrounding page.