Unable to load UI after enabling some experimental features

Uncaught Error: assertion failed: Must use Ember.set() to access this property
    at Object.Ember.assert (vendor.js:12048)
    at Object.set [as createAlerts] (vendor.js:14450)
    at Function.jQuery.extend.jQuery.fn.extend (vendor.js:476)
    at Class.getUserPrefSuccessCallback (app.js:939)
    at Class.newFunc [as getUserPrefSuccessCallback] (vendor.js:12954)
    at Class.opt.success (app.js:166233)
    at fire (vendor.js:1141)
    at Object.fireWith [as resolveWith] (vendor.js:1252)
    at done (vendor.js:8178)
    at XMLHttpRequest.callback (vendor.js:8702)