callback failed for Martin Fowler scrum


```
jhwidvr33vdp3jqppsn7duw37qe?hl=en:371 MediaStreamTrack.getSources is deprecated. See https://www.chromestatus.com/feature/4765305641369600 for more details.
rs=AGyH-FtJGoRgmeo5wKIWMcZ0VoKMun8wOg:98 The MediaStream 'ended' event is deprecated and will be removed in M54, around October 2016. See https://www.chromestatus.com/features/5730404371791872 for more details.
https://hangouts.google.com/hangouts/_/channel/test?VER=8&TYPE=xmlhttp&zx=igi0e2qytrmv Failed to load resource: the server responded with a status of 401 ()
jhwidvr33vdp3jqppsn7duw37qe?hl=en:1 XMLHttpRequest cannot load https://hangouts.google.com/hangouts/_/channel/test?VER=8&TYPE=xmlhttp&zx=igi0e2qytrmv. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://talkgadget.google.com' is therefore not allowed access. The response had HTTP status code 401.
jhwidvr33vdp3jqppsn7duw37qe?hl=en:433 Uncaught (in promise) DOMException: The play() request was interrupted by a new load request.
https://images1-hangout-opensocial.googleusercontent.com/gadgets/proxy?url=…2_f0458a7f051f6c3e7934c3f010ef4632.png&resize_h=32&resize_w=32&refresh=967 Failed to load resource: the server responded with a status of 400 ()
rs=AGyH-FtJGoRgmeo5wKIWMcZ0VoKMun8wOg:4390 Uncaught (in promise) DOMException: The play() request was interrupted by a new load request.
rs=AGyH-FtJGoRgmeo5wKIWMcZ0VoKMun8wOg:4390 Uncaught (in promise) DOMException: The play() request was interrupted by a new load request.
toolboxv2.js:888 'CanvasRenderingContext2D.webkitImageSmoothingEnabled' is deprecated. Please use 'CanvasRenderingContext2D.imageSmoothingEnabled' instead.
ifr?url=app%3A%2F%2F135304697558%2Fhangout&container=hangout&view=default&lang=all&country=ALL&debu…:242 Uncaught TypeError: a[c] is not a function
rs=AGyH-Fsuqnj1lbg84GOF9bbhLrzHJQTKhg:42 Caught exception while dispatching event:
TypeError: Cannot read property 'callbackUrl' of null
at HangoutApplication.sendUrl (https://eq998qatabmpg8td633a9bk8sol8r3nt-a-hangout-opensocial.googleusercon…&parent=https%3A%2F%2Ftalkgadget.google.com&mid=2&authuser=0&hl=en:1466:30)
at HangoutApplication.sendUrl (https://eq998qatabmpg8td633a9bk8sol8r3nt-a-hangout-opensocial.googleusercon…&parent=https%3A%2F%2Ftalkgadget.google.com&mid=2&authuser=0&hl=en:1404:59)
at HangoutApplication.initialize (https://eq998qatabmpg8td633a9bk8sol8r3nt-a-hangout-opensocial.googleusercon…&parent=https%3A%2F%2Ftalkgadget.google.com&mid=2&authuser=0&hl=en:1439:14)
at HangoutApplication.initialize (https://eq998qatabmpg8td633a9bk8sol8r3nt-a-hangout-opensocial.googleusercon…&parent=https%3A%2F%2Ftalkgadget.google.com&mid=2&authuser=0&hl=en:1404:59)
at uc.a (https://eq998qatabmpg8td633a9bk8sol8r3nt-a-hangout-opensocial.googleusercon…&parent=https%3A%2F%2Ftalkgadget.google.com&mid=2&authuser=0&hl=en:1415:19)
at uc.handleEvent (https://plus.google.com/_/scs/talk-static/_/js/k=wcs.platform_stable.en.uBO…k.O/m=platform_stable/rt=j/d=1/rs=AGyH-Fsuqnj1lbg84GOF9bbhLrzHJQTKhg:43:54)
at yd.a.(anonymous function).a.(anonymous function) (https://plus.google.com/_/scs/talk-static/_/js/k=wcs.platform_stable.en.uBO….O/m=platform_stable/rt=j/d=1/rs=AGyH-Fsuqnj1lbg84GOF9bbhLrzHJQTKhg:38:390)
at jc (https://plus.google.com/_/scs/talk-static/_/js/k=wcs.platform_stable.en.uBO….O/m=platform_stable/rt=j/d=1/rs=AGyH-Fsuqnj1lbg84GOF9bbhLrzHJQTKhg:41:660)
at E (https://plus.google.com/_/scs/talk-static/_/js/k=wcs.platform_stable.en.uBO….O/m=platform_stable/rt=j/d=1/rs=AGyH-Fsuqnj1lbg84GOF9bbhLrzHJQTKhg:40:286)
at yd.v (https://plus.google.com/_/scs/talk-static/_/js/k=wcs.platform_stable.en.uBO….O/m=platform_stable/rt=j/d=1/rs=AGyH-Fsuqnj1lbg84GOF9bbhLrzHJQTKhg:66:292)
```