layout id cannot be resolved or is not a field

public class MyClass extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       }
	 String sMyText = "some text";
	 int nMyInt = 10;

 @Override
 protected void onSaveInstanceState(Bundle outState) {
     // Save away the original text, so we still have it if the activity
     // needs to be killed while paused.
     outState.putString("my_text", sMyText);
     outState.putInt("my_int", nMyInt);
     Toast.makeText(this, "onSaveInstanceState()", Toast.LENGTH_LONG).show();
Log.i("onSaveInstanceState", "onSaveInstanceState()");
}
 String sNewMyText = "";
 int nNewMyInt = 0;
 
 @Override
 protected void onRestoreInstanceState(Bundle savedInstanceState) {
     super.onRestoreInstanceState(savedInstanceState);
     // restore saved values
     sNewMyText = savedInstanceState.getString("my_text");
     nNewMyInt = savedInstanceState.getInt("my_int");
     Toast.makeText(this, "onRestoreInstanceState()", Toast.LENGTH_LONG).show();
     Log.i("onRestoreInstanceState", "onRestoreInstanceState()");
     
 }
}

adb kill-server && adb start-server
pause

1. Open Total Commander


2. Open folder with adb.exe usually in
   c:\Program Files\Android\android-sdk-windows\platform-tools\


3. Put into command line command: adb kill-server && adb start-server and press Enter

try {
// your code for example: 
//  LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);         
//  Criteria criteria = new Criteria();
//        provider = locationManager.getBestProvider(criteria, false);
//  locationManager.requestLocationUpdates(provider, 400, 1, this);
        } catch (SecurityException e) {
            e.printStackTrace();
        }

<activity android:name="com.google.android.gms.ads.AdActivity"
              android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
              android:theme="@android:style/Theme.Translucent" />

boolean fc(boolean b) {
	return b;
}// end fc
		boolean bA = true;
		boolean bB = true;
		boolean bC = bA || bB; // true

		bA = true;
		bB = false;
		bC = bA || bB; // true

		bA = false;
		bB = true;
		bC = bA || bB; // true

		bA = false;
		bB = false;
		bC = bA || bB; // false
		
			if(!fc(bB||bA))
			System.out.println("false"); // false
                        else 
			System.out.println("true");