App Crashes after navigating to WebViewScaffold()

I have a simple application where when I click a button, a web view should open with the default URL. When I navigate to the web view and come back, if navigate again to the web view, web view opens and then crashes the whole application.

Here is my code
```
import 'package:flutter/material.dart';
import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';

class MethodsPage extends StatefulWidget {
@override
_MethodsPageState createState() => _MethodsPageState();
}

class _MethodsPageState extends State {
// final flutterWebViewPlugin = FlutterWebviewPlugin();
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text(
'Methods',
style: TextStyle(color: Colors.black),
)),
body: Center(child: RaisedButton(
child: Text('Open View'), onPressed: openWebView,)),
);
}

void openWebView() {
Navigator.push(
context, MaterialPageRoute(builder: (context) => WebUi()));
}

}

class WebUi extends StatelessWidget {
final flutterWebViewPlugin = FlutterWebviewPlugin();
@override
Widget build(BuildContext context) {
return WebviewScaffold(
appBar: AppBar(centerTitle: true,title: Text('Web UI'),),
url: 'https://www.google.com',
withZoom: true,
bottomNavigationBar: BottomAppBar(
child: Row(
children: [
IconButton(
icon: const Icon(Icons.arrow_back_ios),
onPressed: () {
flutterWebViewPlugin.goBack();
},
),
IconButton(
icon: const Icon(Icons.arrow_forward_ios),
onPressed: () {
flutterWebViewPlugin.goForward();
},
),
IconButton(
icon: const Icon(Icons.autorenew),
onPressed: () {
flutterWebViewPlugin.reload();
},
),
],
),
),
);
}
}

```

Error: Received

> F/google-breakpad(21220): -----BEGIN BREAKPAD MICRODUMP-----
> F/google-breakpad(21220): V AndroidWebView:69.0.3497.100
> F/google-breakpad(21220): O A x86 04 i686 google/sdk_gphone_x86_arm/generic_x86_arm:9/PSR1.180720.117/5875966:user/release-keys
> F/google-breakpad(21220): P browser
> F/google-breakpad(21220): R 0000000B SIGSEGV 00000000
> F/google-breakpad(21220): G
> F/google-breakpad(21220): H 12C00000 FFF03000 00DD 3D313000 763FC000 0C:28 0D:12 0E:0A 0F:0F 10:11 11:13 12:56 13:0A 16:02 1B:01 1C:02 1D:01
> F/google-breakpad(21220): S 0 D2087FCC D2087000 00008000
> F/google-breakpad(21220): S D2087000
> ...........
> F/google-breakpad(21220): -----END BREAKPAD MICRODUMP-----
> W/google-breakpad(20716): ### ### ### ### ### ### ### ### ### ### ### ### ###
> W/google-breakpad(20716): Chrome build fingerprint:
> W/google-breakpad(20716): 69.0.3497.100
> W/google-breakpad(20716): 349710017
> W/google-breakpad(20716): ### ### ### ### ### ### ### ### ### ### ### ### ###
> F/libc (20716): Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0 in tid 20808 (RenderThread), pid 20716 (resssdriverlite)
> *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
> Build fingerprint: 'google/sdk_gphone_x86_arm/generic_x86_arm:9/PSR1.180720.117/5875966:user/release-keys'
> Revision: '0'
> ABI: 'x86'
> pid: 20716, tid: 20808, name: RenderThread >>> com.myapp<<<
> signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0
> Cause: null pointer dereference
> eax ec3bf900 ebx e2d85e2c ecx e2c5ba58 edx d2088030
> edi e2eae8f4 esi d2088010
> ebp c50f3000 esp d2087fcc eip 00000000
> backtrace:
> #00 pc 00000000
>

Any assistance would be really helpful.

Start by reproducing the crash on the Android emulator described in the report, using the MethodsPage and WebUi entry points with WebviewScaffold. Read the FlutterWebviewPlugin lifecycle and navigation methods, especially across repeated open-and-back flows. Done means opening, leaving, and reopening the web view no longer crashes the application.

Written by the indexing model from the issue text.