Can not Open Dialogs, NullPointerException at ".show()'

[Md. Jehadul Karim]

    java.lang.RuntimeException: Unable to start activity ComponentInfo{github.mjksabit.sabit.android/github.mjksabit.sabit.android.MainActivity}: android.view.InflateException: Binary XML file line #167 in github.mjksabit.sabit.android:layout/dialog_picker: Binary XML file line #167 in github.mjksabit.sabit.android:layout/dialog_picker: Error inflating class com.google.android.material.floatingactionbutton.FloatingActionButton
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3270)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        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$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: android.view.InflateException: Binary XML file line #167 in github.mjksabit.sabit.android:layout/dialog_picker: Binary XML file line #167 in github.mjksabit.sabit.android:layout/dialog_picker: Error inflating class com.google.android.material.floatingactionbutton.FloatingActionButton
     Caused by: android.view.InflateException: Binary XML file line #167 in github.mjksabit.sabit.android:layout/dialog_picker: Error inflating class com.google.android.material.floatingactionbutton.FloatingActionButton
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Constructor.newInstance0(Native Method)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
        at android.view.LayoutInflater.createView(LayoutInflater.java:854)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:1006)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:961)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:1123)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1084)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:682)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:534)
        at androidx.databinding.DataBindingUtil.inflate(DataBindingUtil.java:126)
        at androidx.databinding.DataBindingUtil.inflate(DataBindingUtil.java:95)
        at ir.androidexception.filepicker.dialog.MultiFilePickerDialog.onCreate(MultiFilePickerDialog.java:56)
        at android.app.Dialog.dispatchOnCreate(Dialog.java:421)
        at android.app.Dialog.show(Dialog.java:315)
        at github.mjksabit.sabit.android.MainActivity.onCreate(MainActivity.java:58)
        at android.app.Activity.performCreate(Activity.java:7802)
        at android.app.Activity.performCreate(Activity.java:7791)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        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$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: java.lang.IllegalArgumentException: The style on this component requires your app theme to be Theme.AppCompat (or a descendant).
        at com.google.android.material.internal.ThemeEnforcement.checkTheme(ThemeEnforcement.java:248)
        at com.google.android.material.internal.ThemeEnforcement.checkAppCompatTheme(ThemeEnforcement.java:218)
        at com.google.android.material.internal.ThemeEnforcement.checkCompatibleTheme(ThemeEnforcement.java:153)
        at com.google.android.material.internal.ThemeEnforcement.obtainStyledAttributes(ThemeEnforcement.java:81)
        at com.google.android.material.floatingactionbutton.FloatingActionButton.<init>(FloatingActionButton.java:212)
        at com.google.android.material.floatingactionbutton.FloatingActionButton.<init>(FloatingActionButton.java:201)
        	... 30 more

My code:

if(permissionGranted(this)) {
            MultiFilePickerDialog multiFilePickerDialog = new MultiFilePickerDialog(getApplicationContext(),
                    () -> Toast.makeText(MainActivity.this, "Canceled!!", Toast.LENGTH_SHORT).show(),
                    files -> Toast.makeText(MainActivity.this, files[0].getPath(), Toast.LENGTH_SHORT).show()
            );
            multiFilePickerDialog.show();
        }
        else{
            requestPermission(this);
        }

[hernaezanthony]

For Android 10, try to add the line below on your manifest inside Application.

android:requestLegacyExternalStorage="true"

[Md. Jehadul Karim]

@hernaezanthony already did that

[Saleh Yarahmadi]

@hernaezanthony already did that

Add material design library and test again.