Visual Studio 2015 with Microsoft Edge, Unexpected Error starting up the application. Assignment to read-only properties is not allowed in strict mode

Visual Studio 2015 with Microsoft Edge, Unexpected Error starting up the application. Assignment to read-only properties is not allowed in strict mode

The error message in the title comes up in an alert box when I start my application from Microsoft Visual Studio 2015 using Microsoft Edge as the browser.

Its OK in IE11 and Firefox.

Initially I thought it was something about Edge and VS2015, but actually when I did a hello world app or a fiddle, it didn't happen. So a lot of alert statements later I found the problem, it turned out that this bad line of code was accidentally left in there:

$(document).on("focus", "input,textarea,select,button");

i.e. an "on" event without a function provided. I thought perhaps the jQuery developers could improve this behaviour by checking if the function parameter was undefined.

thanks