Solved: Object doesn’t support property or method ‘assign’

Object.assign() method is not supported in IE, but there is a polyfill available

Put the below line of code to your <head> for solving this issue.
<script> if (typeof Object.assign != 'function') { (function() { Object.assign = function(target) { 'use strict'; if (target === undefined || target === null) { throw new TypeError('Cannot convert undefined or null to object'); } var output = Object(target); for (var index = 1; index < arguments.length; index++) { var source = arguments[index]; if (source !== undefined && source !== null) { for (var nextKey in source) { if (source.hasOwnProperty(nextKey)) { output[nextKey] = source[nextKey]; } } } } return output; }; })(); } </script>