title: (android studio) can't change the "Webpage not available" page in webview
body: <p>I'm trying to display my own "no internet" page in my app.
  I think something might be wrong with my code, I've been following <a href="https://www.youtube.com/watch?v=6-0kiZHCtjc" rel="nofollow noreferrer">this</a> tutorial but for some reason, my code keeps displaying the default "Webpage not available" screen.</p>
  
  <pre><code>public class MainActivity extends AppCompatActivity {
  
      private WebView webView;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          webView = (WebView) findViewById(R.id.webview);
          WebSettings webSettings = webView.getSettings();
          webSettings.setJavaScriptEnabled(true);
          webSettings.setAppCacheEnabled(true);
          webView.loadUrl("https://www.kasumushi.com/");
  
          webView.setWebViewClient(new WebViewClient() {
              public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                  webView.loadUrl("file:///android_asset/error.html");
  
              }
          });
      }
  
      @Override
      public void onBackPressed() {
          if(webView.canGoBack()) {
              webView.goBack();
          }else {
              super.onBackPressed();
          }
      }
  
  }
  </code></pre>