TypeError: this._didCreateEngineInitializerResolve is not a function

Question

I updated Flutter SDK yesterday and since then my web app doesn't run. I just see a white screen and in the console/log I see this error:

Do not call didCreateEngineInitializer by hand. Start with loadEntrypoint instead.

Uncaught (in promise) TypeError: this._didCreateEngineInitializerResolve is not a function
    at FlutterLoader._didCreateEngineInitializer (flutter.js:61:12)
    at webOnlyWarmupEngine (initialization.dart:97:12)
    at webOnlyWarmupEngine.next (<anonymous>)
    at runBody (async_patch.dart:84:54)
    at Object._async [as async] (async_patch.dart:123:5)
    at Object.webOnlyWarmupEngine (initialization.dart:63:33)
    at main (web_entrypoint.dart:19:12)
    at main.next (<anonymous>)
    at runBody (async_patch.dart:84:54)
    at Object._async [as async] (async_patch.dart:123:5)
    at main$ (web_entrypoint.dart:18:18)
    at main_module.bootstrap.js:19:10
    at Array.forEach (<anonymous>)
    at window.$dartRunMain (main_module.bootstrap.js:18:32)
    at <anonymous>:1:8
    at Object.runMain (client.js:8790:21)
    at client.js:24706:19
    at _wrapJsFunctionForAsync_closure.$protected (client.js:3471:15)
    at _wrapJsFunctionForAsync_closure.call$2 (client.js:11541:12)
    at Object._asyncStartSync (client.js:3435:20)
    at main__closure4.$call$body$main__closure (client.js:24719:16)
    at main__closure4.call$1 (client.js:24645:19)
    at StaticClosure._rootRunUnary (client.js:3833:18)
    at _CustomZone.runUnary$2$2 (client.js:12941:39)
    at _CustomZone.runUnaryGuarded$1$2 (client.js:12888:14)
    at _ForwardingStreamSubscription._sendData$1 (client.js:12481:19)
    at _ForwardingStreamSubscription._add$1 (client.js:12427:15)
    at _ForwardingStreamSubscription._add$1 (client.js:12763:12)
    at _MapStream._handleData$2 (client.js:12824:12)
    at _ForwardingStreamSubscription._handleData$1 (client.js:12789:20)
    at tear_off.<anonymous> (client.js:1388:45)
    at StaticClosure._rootRunUnary (client.js:3833:18)
    at _CustomZone.runUnary$2$2 (client.js:12941:39)
    at _CustomZone.runUnaryGuarded$1$2 (client.js:12888:14)
    at _ControllerSubscription._sendData$1 (client.js:12481:19)
    at _ControllerSubscription._add$1 (client.js:12427:15)
    at _SyncStreamController._sendData$1 (client.js:12275:32)
    at _SyncStreamController.add$1 (client.js:12156:15)
    at tear_off.<anonymous> (client.js:1446:48)
    at StaticClosure._rootRunUnary (client.js:3833:18)
    at _CustomZone.runUnary$2$2 (client.js:12941:39)
    at _CustomZone.runUnaryGuarded$1$2 (client.js:12888:14)
    at _ControllerSubscription._sendData$1 (client.js:12481:19)
    at _ControllerSubscription._add$1 (client.js:12427:15)
    at _SyncStreamController._sendData$1 (client.js:12275:32)
    at _SyncStreamController.add$1 (client.js:12156:15)
    at _GuaranteeSink.add$1 (client.js:24124:25)
    at HtmlWebSocketChannel_closure1.call$1 (client.js:24430:10)
    at _EventStreamSubscription_closure.call$1 (client.js:17925:26)
    at StaticClosure._rootRunUnary (client.js:3839:16)
    at _CustomZone.runUnary$2$2 (client.js:12941:39)
    at _CustomZone.runUnaryGuarded$1$2 (client.js:12888:14)
    at _CustomZone_bindUnaryCallbackGuarded_closure.call$1 (client.js:13078:25)
    at invokeClosure (client.js:1277:26)
    at WebSocket.<anonymous> (client.js:1296:18)

It looks like the error is coming from the auto generated flutter.js file. In that file there is this method:

_didCreateEngineInitializer(engineInitializer) {
      if (typeof this._didCreateEngineInitializerResolve != "function") {
        console.warn("Do not call didCreateEngineInitializer by hand. Start with loadEntrypoint instead.");
      }
      this._didCreateEngineInitializerResolve(engineInitializer);
      // Remove the public method after it's done, so Flutter Web can hot restart.
      delete this.didCreateEngineInitializer;
    }

The line that causes the exceptions is this:

this._didCreateEngineInitializerResolve(engineInitializer);

I have tried cleaning and rebuilding but the files gets created with the same code and I keep getting the same error.

flutter.js is added as a script in the index.html file. Here is index.html content:

<!DOCTYPE html>
<html>
<head>

  <meta charset="UTF-8">
  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
  <meta name="description" content="Space Shuttle web application.">

  <!-- iOS meta tags & icons -->
  <meta name="apple-mobile-web-app-capable" content="yes">
  <meta name="apple-mobile-web-app-status-bar-style" content="black">
  <meta name="apple-mobile-web-app-title" content="space_shuttle_web_application">
  <link rel="apple-touch-icon" href="icons/Icon-192.png">

  <!-- Favicon -->
  <link rel="icon" type="image/png" href="favicon.png"/>

  <title>space_shuttle_web_application</title>
  <link rel="manifest" href="manifest.json">

  <script>
    // The value below is injected by flutter build, do not touch.
    var serviceWorkerVersion = null;
  </script>
  <!-- This script adds the flutter initialization JS code -->
  <script src="flutter.js" defer></script>

  <script src="https://js.stripe.com/v3/"></script>
</head>
<body>
<script src="https://www.gstatic.com/firebasejs/9.13.0/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/9.13.0/firebase-firestore.js"></script>
<script>
      var firebaseConfig = {
        apiKey: "..",
        authDomain: "...",
        databaseURL: "...",
        projectId: "...",
        storageBucket: "...",
        messagingSenderId: "...",
        appId: "...",
        measurementId: "...",
      };

      // Initialize Firebase
      firebase.initializeApp(firebaseConfig);
      firebase.analytics();
    </script>
<script>
    if ('serviceWorker' in navigator) {
      window.addEventListener('load', function () {
        navigator.serviceWorker.register('flutter_service_worker.js');
      });
    }
  </script>
<script src="main.dart.js" type="application/javascript"></script>

</body>
</html>

Answer 1

If anyone is facing this issue. The problem is indeed in the index.html file. The issue wasn't the flutter upgrade. The issue I think is in this part:

<script>
    if ('serviceWorker' in navigator) {
      window.addEventListener('load', function () {
        navigator.serviceWorker.register('flutter_service_worker.js');
      });
    }
</script>

I replaced it with:

<script>
    window.addEventListener('load', function(ev) {
      // Download main.dart.js
      _flutter.loader.loadEntrypoint({
        serviceWorker: {
          serviceWorkerVersion: serviceWorkerVersion,
        }
      }).then(function(engineInitializer) {
        return engineInitializer.initializeEngine();
      }).then(function(appRunner) {
        return appRunner.runApp();
      });
    });
  </script>

And it fixed the error.