Created attachment 387331 [details] safari eventsource with close When using EventSource (https://developer.mozilla.org/en-US/docs/Web/API/EventSource) library in Safari 13, with closing the connection when done, Ex: var source = new window.EventSource("someurl"); source.onmessage = function(event) { source.close(); }; I am getting error in WebInspector inspite the status code is 200. Means behaviour is as intended, only showing error in WebInspector UI. I have explained in image the same. Image: bug-safari-eventsource-close.jpeg When we are not closing the EventSource object it works fine #source.close() Can we solve this ? Link: https://jsfiddle.net/parikhdhruvesh1/kxos7yjz/24/