Exception on IE11 due to null reference

[aebsubis]

I have recently started testing my application using Internet Explorer 11. I have never had this problem before with either Chrome or Firefox.

Apparently the canResize method obtains a null reference to the parent and then tries to execute "querySelector" on it.

ORIGINAL EXCEPTION: Unable to get property 'querySelector' of undefined or null reference
TypeError: Unable to get property 'querySelector' of undefined or null reference
   at NgGridItem.prototype.canResize (Unknown script code:1079:13)
   at NgGridItem.prototype.onMouseMove (Unknown script code:1115:18)
   at NgGrid.prototype.onMouseMove (Unknown script code:324:17)
   at _View_Dashboard0.prototype._handle_mousemove_6_1 (Function code:244:3)
   at Anonymous function (Unknown script code:9698:21)
   at Anonymous function (Unknown script code:1877:13)
   at Anonymous function (Unknown script code:1990:108)
   at ZoneDelegate.prototype.invoke (https://localhost/lib/js/zone.js:201:13)
   at onInvoke (Unknown script code:6242:25)
   at ZoneDelegate.prototype.invoke (https://localhost/lib/js/zone.js:201:13)