Android błąd z Activity

Question

Witam tworze aplikacje mobilną na androida i mam problem iż gdy po wciśnięciu przycisku logowanie przez Googla 

aplikacja crashuje się . Mógłby ktoś mi pokazać przyczynę i jak ją naprawić?

Główne activity z przyciskiem.

public class MainActivity extends AppCompatActivity {
    GoogleSignInClient mGoogleSignInClient;
    private int RC_SIGN_IN = 3;
    SignInButton signInButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        signInButton = findViewById(R.id.sign_in_button);

        signInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                switch (view.getId()) {
                    case R.id.sign_in_button:
                        signIn();
                        break;
                    // ...
                }
            }
        });
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();

        mGoogleSignInClient = GoogleSignIn.getClient(this, gso);

    }
    private void signIn() {
        Intent signInIntent = mGoogleSignInClient.getSignInIntent();
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        // Result returned from launching the Intent from GoogleSignInClient.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            // The Task returned from this call is always completed, no need to attach
            // a listener.
            Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
            handleSignInResult(task);
        }
    }
    private void handleSignInResult(Task<GoogleSignInAccount> completedTask) {
        try {
            GoogleSignInAccount account = completedTask.getResult(ApiException.class);

            Intent intent = new Intent(MainActivity.this, MenuActivity.class);
            startActivity(intent);
        } catch (ApiException e) {
            // The ApiException status code indicates the detailed failure reason.
            // Please refer to the GoogleSignInStatusCodes class reference for more information.
            Log.w("TAG", "signInResult:failed code=" + e.getStatusCode());
            // updateUI(null);
        }
    }
}

Activity docelowe po zalogowaniu:

public class MenuActivity extends AppCompatActivity  {

    GoogleSignInClient mGoogleSignInClient;
    Button logoutBtn;
    TextView userName;
    ImageView profileImage;
    private GoogleSignInOptions gso;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();

        mGoogleSignInClient = GoogleSignIn.getClient(this, gso);

        logoutBtn=(Button)findViewById(R.id.button_wyl);
        profileImage=(ImageView)findViewById(R.id.profileImage);
        userName = findViewById(R.id.name);
        logoutBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                switch (view.getId()) {
                    // ...
                    case R.id.button_wyl:
                        signOut();
                        break;
                    // ...
                }
            }
        });

        GoogleSignInAccount acct = GoogleSignIn.getLastSignedInAccount(this);
        if (acct != null) {
            String personName = acct.getDisplayName();
            Uri personPhoto = acct.getPhotoUrl();

            userName.setText(personName);
            Glide.with(this).load(String.valueOf(personPhoto)).into(profileImage);

        }
    }

    private void signOut() {
        mGoogleSignInClient.signOut()
                .addOnCompleteListener(this, new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        Toast.makeText(MenuActivity.this, "Signed out Successfully", Toast.LENGTH_LONG).show();
                        finish();
                    }
                });
    }
}

Oraz błąd niżej:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.goodmath, PID: 25316
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.goodmath/com.example.goodmath.MenuActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.example.goodmath.MenuActivity.onCreate(MenuActivity.java:46)
        at android.app.Activity.performCreate(Activity.java:7136)
        at android.app.Activity.performCreate(Activity.java:7127)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:193) 
        at android.app.ActivityThread.main(ActivityThread.java:6669) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)