Вылетает приложение Android Studio⁠⁠

Вот лог (брал через Logcat):

2020-05-21 22:20:20.558 13374-13374/com.example.easyclass E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.example.easyclass, PID: 13374

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.easyclass/com.example.easyclass.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.appcompat.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3341)

at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3485)

at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)

at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)

at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2045)

at android.os.Handler.dispatchMessage(Handler.java:106)

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)

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.appcompat.app.ActionBar.setDisplayHomeAsUpEnabled(boolean)' on a null object reference

at androidx.navigation.ui.ActionBarOnDestinationChangedListener.setNavigationIcon(ActionBarOnDestinationChangedListener.java:58)

at androidx.navigation.ui.AbstractAppBarOnDestinationChangedListener.setActionBarUpIndicator(AbstractAppBarOnDestinationChangedListener.java:118)

at androidx.navigation.ui.AbstractAppBarOnDestinationChangedListener.onDestinationChanged(AbstractAppBarOnDestinationChangedListener.java:107)

at androidx.navigation.NavController.addOnDestinationChangedListener(NavController.java:218)

at androidx.navigation.ui.NavigationUI.setupActionBarWithNavController(NavigationUI.java:220)

at com.example.easyclass.MainActivity.onCreate(MainActivity.java:45)

at android.app.Activity.performCreate(Activity.java:7989)

at android.app.Activity.performCreate(Activity.java:7978)

at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3316)

at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3485)

at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)

at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)

at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2045)

at android.os.Handler.dispatchMessage(Handler.java:106)

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)