While login i am getting transition superseded error

I have completed the tutorial, but when I login or register I am getting transition superseded error. Also because of this, the application is not able to fetch channels, gravatar, and online people. And after login when I reload the application then it works fine without any errors. I am using angular v1.6.1 and angular-ui-router v0.3.2.
I also pulled the latest code in branch 01 and still facing the same issue.

Below are the stack traces

- `angular.js:14328 Error: transition superseded
at $StateProvider.$get (http://localhost:4000/bower_components/angular-ui-router/release/angular-ui-router.js:2909:37)
at Object.invoke (http://localhost:4000/bower_components/angular/angular.js:4842:19)
at http://localhost:4000/bower_components/angular/angular.js:4636:37
at Object.getService [as get] (http://localhost:4000/bower_components/angular/angular.js:4783:32)
at http://localhost:4000/bower_components/angular-ui-router/release/angular-ui-router.js:3696:17
at Object.invoke (http://localhost:4000/bower_components/angular/angular.js:4842:19)
at http://localhost:4000/bower_components/angular/angular.js:4645:62
at forEach (http://localhost:4000/bower_components/angular/angular.js:357:20)
at createInjector (http://localhost:4000/bower_components/angular/angular.js:4645:3)
at doBootstrap (http://localhost:4000/bower_components/angular/angular.js:1838:20) Possibly unhandled rejection: {}
(anonymous) @ angular.js:14328
(anonymous) @ angular.js:10837
processChecks @ angular.js:16674
$eval @ angular.js:17972
$digest @ angular.js:17786
(anonymous) @ angular.js:18011
completeOutstandingRequest @ angular.js:6111
(anonymous) @ angular.js:6390
`
- `angular.js:14328 Error: [$interpolate:interr] Can't interpolate: {{ channelsCtrl.getGravatar(channelsCtrl.profile.$id) }}
TypeError: Cannot read property 'emailHash' of undefined
http://errors.angularjs.org/1.6.1/$interpolate/interr?p0=%7B%7B%20channelsC…&p1=TypeError%3A%20Cannot%20read%20property%20'emailHash'%20of%20undefined
at angular.js:68
at Function.$interpolateMinErr.interr (angular.js:12487)
at interpolationFn (angular.js:12800)
at Object.attrInterpolatePreLinkFn (angular.js:10143)
at angular.js:1291
at invokeLinkFn (angular.js:10252)
at nodeLinkFn (angular.js:9618)
at compositeLinkFn (angular.js:8881)
at compositeLinkFn (angular.js:8884)
at compositeLinkFn (angular.js:8884)
`

- `TypeError: Cannot read property 'emailHash' of undefined
at Object.getGravatar (users.service.js:15)
at fn (eval at compile (angular.js:1), :4:356)
at expressionInputWatch (angular.js:16157)
at Scope.$digest (angular.js:17806)
at angular.js:18011
at completeOutstandingRequest (angular.js:6111)
at angular.js:6390
`