App Crashes whenever I click an Icon on Navigation bar - android-studio

Question

Just got many problems sorted out on my bottom navigation bar, but now the app crashes whenever I click on any of the 3 navigation bar Icons.
Error
2020-07-23 15:41:26.397 25876-25876/com.example.sociate11 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.sociate11, PID: 25876
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference
at androidx.fragment.app.FragmentTransaction.doAddOp(FragmentTransaction.java:245)
at androidx.fragment.app.BackStackRecord.doAddOp(BackStackRecord.java:180)
at androidx.fragment.app.FragmentTransaction.replace(FragmentTransaction.java:343)
at androidx.fragment.app.FragmentTransaction.replace(FragmentTransaction.java:293)
at com.example.sociate11.activityHome$2.onNavigationItemSelected(activityHome.java:67)
at com.google.android.material.bottomnavigation.BottomNavigationView$1.onMenuItemSelected(BottomNavigationView.java:243)
at androidx.appcompat.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:840)
at androidx.appcompat.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:158)
at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:991)
at com.google.android.material.bottomnavigation.BottomNavigationMenuView$1.onClick(BottomNavigationMenuView.java:124)
at android.view.View.performClick(View.java:7357)
at android.view.View.performClickInternal(View.java:7334)
at android.view.View.access$3600(View.java:808)
at android.view.View$PerformClick.run(View.java:28200)
at android.os.Handler.handleCallback(Handler.java:907)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7478)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)
activityHome.java
package com.example.sociate11;
import android.content.Intent;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import com.google.android.material.bottomnavigation.BottomNavigationView;
import com.google.firebase.auth.FirebaseAuth;
public class activityHome extends AppCompatActivity {
private FirebaseAuth firebaseAuth;
private Button logout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
firebaseAuth = FirebaseAuth.getInstance();
logout = (Button)findViewById(R.id.btnLogOut);
logout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
firebaseAuth.signOut();
finish();
startActivity(new Intent(activityHome.this, MainActivity.class));
}
});
BottomNavigationView bottomNav = findViewById(R.id.bottom_navigation_bar);
bottomNav.setOnNavigationItemSelectedListener(navListener);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
new HomeFragment()).commit();
}
}
private BottomNavigationView.OnNavigationItemSelectedListener navListener =
new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.home_fragment:
selectedFragment = new HomeFragment();
break;
case R.id.events_fragment:
selectedFragment = new EventFragment();
break;
case R.id.fragment_myconversation:
selectedFragment = new ConversationFragment();
break;
}
assert selectedFragment != null;
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
selectedFragment).commit();
return true;
}
};
}
ConversationsFragment.java (all 3 fragments are currently identical)
package com.example.sociate11;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
public class ConversationFragment extends Fragment {
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_myconversations,container,false);
}
}
bottom_navigation.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="#+id/menu_home"
android:title="Home"
android:icon="#drawable/ic_home"
app:showAsAction="always"/>
<item
android:id="#+id/menu_myEvents"
android:title="My Events"
android:icon="#drawable/ic_event"
app:showAsAction="always"/>
<item
android:id="#+id/menu_myConversations"
android:title="My Conversations"
android:icon="#drawable/ic_conversations"
app:showAsAction="always"/>
</menu>
activity_home.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activityHome"
android:background="#color/colorPrimary">
<Button
android:id="#+id/btnLogOut"
android:layout_width="115dp"
android:layout_height="75dp"
android:text="log out"
android:textSize="18sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#id/bottom_navigation_bar" />
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottom_navigation_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?android:attr/windowBackground"
app:itemTextColor="#color/colorPrimaryDark"
app:itemIconTint="#color/colorPrimaryDark"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/btnLogOut"
app:layout_constraintVertical_bias="1.0"
app:menu="#menu/bottom_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>
Thank you for the help as always, and please let me know if I didn't provide enough info!