TypeError: Attempted to assign to readonly property. ring.js: Line 333 <p>I have two Mac systems with different Safari versions. I'm facing this problem in Safari version <strong>9.0.1</strong>, while it works fine in version <strong>8.0</strong>.</p> <p><a href="https://discussions.apple.com/thread/7306139" rel="nofollow">THIS</a> support blog mentions a similar issue. While I don't find this error in other browsers like Chrome or Firefox in both the Macs, but the Safari versions seems to create problem.</p> <p>I came across a unaccepted solution <a href="http://stackoverflow.com/questions/25174594/typeerror-attempted-to-assign-to-readonly-property-on-ios8-safari">HERE</a>, that suggests to remove <code>"use strict"</code> and that solves my problem (I have removed it from Line 28 of <strong>ring.js</strong>). But, I'm not sure about what side effects this may have. While I read the advantages of <strong>Why Strict Mode?</strong> <a href="http://www.w3schools.com/js/js_strict.asp" rel="nofollow">HERE</a>, I wonder why a modern browser(Safari 9.0.1) doesn't support it.</p> <p>Can anyone throw some light to this?</p>