ember-data 2.14.0: Assertion Failed: You modified "model.players" twice on ... in a single render.

[ghost]

Just updating ember-data to 2.14.0 from 2.13.1 I have this following error.

NodeJs 7.10.0 - npm 5.0.3

Assertion Failed: You modified "model.players" twice on <myapp@model:team::ember767:1> in a single render. It was rendered in "template:myapp/templates/team.hbs" and modified in "template:myapp/templates/team.hbs". This was unreliable and slow in Ember 1.x and is no longer supported. See https://github.com/emberjs/ember.js/issues/13948 for more details.
Error
    at assert (http://localhost:4200/assets/vendor.js:18622:13)
    at Object.assert (http://localhost:4200/assets/vendor.js:18835:34)
    at http://localhost:4200/assets/vendor.js:35859:27
    at runInDebug (http://localhost:4200/assets/vendor.js:18735:5)
    at Object.runInDebug (http://localhost:4200/assets/vendor.js:18859:38)
    at Object.assertNotRendered (http://localhost:4200/assets/vendor.js:35833:23)
    at Object.propertyDidChange (http://localhost:4200/assets/vendor.js:34476:30)
    at Class.propertyDidChange (http://localhost:4200/assets/vendor.js:47793:19)
    at Class.notifyPropertyChange (http://localhost:4200/assets/vendor.js:47807:12)
    at InternalModel.notifyPropertyChange (http://localhost:4200/assets/vendor.js:79047:20)
defaultDispatch @ ember.debug.js:19818
dispatchError @ ember.debug.js:19797
invokeWithOnError @ ember.debug.js:2200
flush @ ember.debug.js:2256
flush @ ember.debug.js:2380
end @ ember.debug.js:2450
(anonymous) @ ember.debug.js:3016

My package.json:

"broccoli-asset-rev": "^2.5.0",
"ember-ajax": "^3.0.0",
"ember-cli": "2.13.2",
"ember-cli-app-version": "^3.0.0",
"ember-cli-babel": "^6.4.1",
"ember-cli-babili": "^0.2.0",
"ember-cli-code-coverage": "^0.3.12",
"ember-cli-dependency-checker": "^2.0.0",
"ember-cli-deploy": "^1.0.1",
"ember-cli-eslint": "^3.1.0",
"ember-cli-htmlbars": "^2.0.2",
"ember-cli-htmlbars-inline-precompile": "^0.4.3",
"ember-cli-inject-live-reload": "^1.6.1",
"ember-cli-qunit": "^4.0.0",
"ember-cli-sass": "^6.2.0",
"ember-cli-shims": "^1.1.0",
"ember-cli-sri": "^2.1.1",
"ember-data": "2.14.0",
"ember-export-application-global": "^2.0.0",
"ember-load-initializers": "^1.0.0",
"ember-resolver": "^4.1.0",
"ember-responsive": "^2.0.4",
"ember-simple-auth": "^1.3.0",
"ember-source": "~2.13.3",
"loader.js": "^4.5.0",
"run-sequence": "~1.2.2"

team.hbs:

{{#each model.players key="id" as |player index|}}
  <a href="[somerUrl]" class="{{player.statusClass}}">
    <span>{{player.code}}</span>
    {{#if player.isOk}}
      {{#each player.fighters.content as |fighter|}}
        <div class="fighter {{fighter.fighterClass}}">{{fighter.fighterText}}</div>
      {{/each}}
    {{/if}}
  </a>
  {{else}}
  {{#if model.players.isPending}}
    Loading...
  {{else}}
    Nothing to show.
  {{/if}}
{{/each}}

Why this error?

[runspired]

You are likely either loading data twice in the same render or mutating that data within the same render. I would suggest asking for help on Slack.

[ghost]

Yes, but I don't understand where. And with ember-data 2.13.1 it works good.

[sly7-7]

I encounter exactly the same symptoms switching from 2.13.x to 2.14.x. I did'nt have the time to dig in further now, but I will do asap.

[workmanw]

I also saw something similar when running ember-try with 2.14, but we're still stuck on 2.12 until #4986 is fixed up, so I didn't bother to dive in too deeply. It's definitely possible we're doing something goofy that just happened to work before and a change in 2.14 exposed it.

[BryanCrotaz]

I have this with a vanilla adapter and serialiser generating jsonapi from a non standard json backend. Just overriding normalise and using store.find

[tschoartschi]

I have the same problem. And like @johnunclesam I don't get it where I try to load the data twice... There is also another issue which looks very similar: #4942 not sure if it is an issue with my/our code or an issue with ember-data. Maybe someone has an idea how to debug this problem. I'm pretty much lost in the huge stacktrace.

[nerdyworm]

Same issue. Although #4942 looks like it is the root of the issue.