'dart:ui/text.dart': Failed assertion: line 1372: '<optimized out>': is not true

[ahmedgulabkhan]

The following error shows while running the project with all the required dependencies. Error is present in the TextField() widget of the 'search.dart' file of this project.

════════ Exception caught by rendering library ═════════════════════════════════════════════════════
The following assertion was thrown during paint():
'dart:ui/text.dart': Failed assertion: line 1372: '': is not true.

Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
https://github.com/flutter/flutter/issues/new?template=BUG.md

[akshaybalaji123]

@ahmedgulabkhan Launching lib\main.dart on sdk gphone x86 arm in debug mode...
Running Gradle task 'assembleDebug'...
✓ Built build\app\outputs\flutter-apk\app-debug.apk.
Installing build\app\outputs\flutter-apk\app.apk...
Waiting for sdk gphone x86 arm to report its views...
Debug service listening on ws://127.0.0.1:65280/yj6K69WaXFE=/ws
Syncing files to device sdk gphone x86 arm...

════════ Exception caught by widgets library
══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following FirebaseException was thrown building Builder:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

The relevant error-causing widget was:
MaterialApp file:///C:/Users/aksha/Downloads/chatapp/chat_app_tutorial/lib/main.dart:13:12

When the exception was thrown, this was the stack:
#0 MethodChannelFirebase.app (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:118:5)
#1 Firebase.app (package:firebase_core/src/firebase.dart:52:41)
#2 FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:37:47)
#3 new AuthMethods (package:chat_app_tutorial/services/auth.dart:6:42)
#4 new _SignupState (package:chat_app_tutorial/views/signup.dart:14:33)
#5 Signup.createState (package:chat_app_tutorial/views/signup.dart:7:33)
#6 new StatefulElement (package:flutter/src/widgets/framework.dart:4635:25)
#7 StatefulWidget.createElement (package:flutter/src/widgets/framework.dart:900:38)
... Normal element mounting (132 frames)
#139 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#140 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5991:32)
... Normal element mounting (258 frames)
#398 Element.inflateWidget (package:flutter/src/widgets/framework.dart:3490:14)
#399 Element.updateChild (package:flutter/src/widgets/framework.dart:3258:18)
#400 RenderObjectToWidgetElement._rebuild (package:flutter/src/widgets/binding.dart:1174:16)
#401 RenderObjectToWidgetElement.mount (package:flutter/src/widgets/binding.dart:1145:5)
#402 RenderObjectToWidgetAdapter.attachToRenderTree. (package:flutter/src/widgets/binding.dart:1087:17)
#403 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2620:19)
#404 RenderObjectToWidgetAdapter.attachToRenderTree (package:flutter/src/widgets/binding.dart:1086:13)
#405 WidgetsBinding.attachRootWidget (package:flutter/src/widgets/binding.dart:927:7)
#406 WidgetsBinding.scheduleAttachRootWidget. (package:flutter/src/widgets/binding.dart:908:7)
(elided 11 frames from class _RawReceivePortImpl, class _Timer, dart:async, and dart:async-patch)

════════════════════════════════════════════════════════════════════════════════════════════════════
═══════════════════════════════════════════════════════
The following FirebaseException was thrown building Builder:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

The relevant error-causing widget was:
MaterialApp file:///C:/Users/aksha/Downloads/chatapp/chat_app_tutorial/lib/main.dart:13:12
When the exception was thrown, this was the stack:
#0 MethodChannelFirebase.app (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:118:5)
#1 Firebase.app (package:firebase_core/src/firebase.dart:52:41)
#2 FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:37:47)
#3 new AuthMethods (package:chat_app_tutorial/services/auth.dart:6:42)
#4 new _SignupState (package:chat_app_tutorial/views/signup.dart:14:33)
...
I am getting this error