Linha de arquivo XML binário # 0: Erro ao inflar a classe <unknown>

Erro ao executar um jogo de perguntas. Algo assim (quando a atividade de jogo é aberta). Meu aplicativo é interrompido e ocorre um erro de arquivo XML binário na linha 0. É meio estranho, porque eu não vi problema assim com a linha 0, então eu preciso da sua ajuda, pessoal. Obrigado!

E/AndroidRuntime: FATAL EXCEPTION: main
   Process: sarveshchavan777.triviaquiz, PID: 2901
   java.lang.RuntimeException: Unable to start activity ComponentInfo{sarveshchavan777.triviaquiz/sarveshchavan777.triviaquiz.MainGameActivity}: android.view.InflateException: Binary XML file line #0: Binary XML file line #0: Error inflating class <unknown>
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
       at android.app.ActivityThread.-wrap11(Unknown Source:0)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
       at android.os.Handler.dispatchMessage(Handler.java:105)
       at android.os.Looper.loop(Looper.java:164)
       at android.app.ActivityThread.main(ActivityThread.java:6540)
       at java.lang.reflect.Method.invoke(Native Method)
       at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
    Caused by: android.view.InflateException: Binary XML file line #0: Binary XML file line #0: Error inflating class <unknown>
    Caused by: android.view.InflateException: Binary XML file line #0: Error inflating class <unknown>
    Caused by: java.lang.reflect.InvocationTargetException
       at java.lang.reflect.Constructor.newInstance0(Native Method)
       at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
       at android.view.LayoutInflater.createView(LayoutInflater.java:650)
       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:793)
       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733)
       at android.view.LayoutInflater.rInflate(LayoutInflater.java:866)
       at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:827)
       at android.view.LayoutInflater.rInflate(LayoutInflater.java:869)
       at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:827)
       at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
       at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
       at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
       at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:288)
       at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143)
       at sarveshchavan777.triviaquiz.MainGameActivity.onCreate(MainGameActivity.java:36)
       at android.app.Activity.performCreate(Activity.java:6980)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
       at android.app.ActivityThread.-wrap11(Unknown Source:0)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
       at android.os.Handler.dispatchMessage(Handler.java:105)
       at android.os.Looper.loop(Looper.java:164)
       at android.app.ActivityThread.main(ActivityThread.java:6540)
       at java.lang.reflect.Method.invoke(Native Method)
       at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
    Caused by: java.lang.UnsupportedOperationException: Can't convert value at index 1 to color: type=0x5
       at android.content.res.TypedArray.getColor(TypedArray.java:473)
       at info.hoang8f.widget.FButton.parseAttrs(FButton.java:116)
       at info.hoang8f.widget.FButton.<init>(FButton.java:52)
       at java.lang.reflect.Constructor.newInstance0(Native Method) 
       at java.lang.reflect.Constructor.newInstance(Constructor.java:334) 
       at android.view.LayoutInflater.createView(LayoutInflater.java:650) 
       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:793) 
       at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733) 
       at android.view.LayoutInflater.rInflate(LayoutInflater.java:866) 
       at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:827) 
       at android.view.LayoutInflater.rInflate(LayoutInflater.java:869) 
       at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:827) 
       at android.view.LayoutInflater.inflate(LayoutInflater.java:518) 
       at android.view.LayoutInflater.inflate(LayoutInflater.java:426) 
       at android.view.LayoutInflater.inflate(LayoutInflater.java:377) 
       at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:288) 
       at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143) 
       at sarveshchavan777.triviaquiz.MainGameActivity.onCreate(MainGameActivity.java:36) 
       at android.app.Activity.performCreate(Activity.java:6980) 
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213) 
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770) 
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892) 
       at android.app.ActivityThread.-wrap11(Unknown Source:0) 
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593) 
       at android.os.Handler.dispatchMessage(Handler.java:105) 
       at android.os.Looper.loop(Looper.java:164) 
       at android.app.ActivityThread.main(ActivityThread.java:6540) 
       at java.lang.reflect.Method.invoke(Native Method) 
       at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) 

Onde MainGameActivity.java:36 está:setContentView(R.layout.activity_game_main);

activity_game_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:fbutton="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/backgroundColor"
    android:orientation="vertical"
    tools:context="sarveshchavan777.triviaquiz.MainGameActivity">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/lightGreen"
        android:minHeight="?actionBarSize">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="0dp">



            <TextView
                android:id="@+id/triviaQuizText"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center"
                android:text="@string/app_name"
                android:textColor="@color/white"
                android:textSize="25sp"
                android:layout_toLeftOf="@+id/timeText"
                android:layout_toRightOf="@+id/coinText" />

            <TextView
                android:id="@+id/timeText"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:paddingLeft="10dp"
                android:gravity="center"
                android:paddingRight="10dp"
                android:text="@string/time"
                android:textSize="20sp" />

        </RelativeLayout>
    </android.support.v7.widget.Toolbar>

    <View
        android:layout_width="match_parent"
        android:layout_height="10dp"></View>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight=".5"
        android:background="@color/white"
        android:orientation="vertical">

        <TextView
            android:id="@+id/triviaQuestion"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="20dp"
            android:gravity="center"
            android:text="@string/question"
            android:textColor="@color/grey"
            android:textSize="18sp" />

        <TextView
            android:id="@+id/resultText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text=""
            android:textColor="@color/green"
            android:textSize="30sp" />
    </LinearLayout>


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:gravity="center"
        android:orientation="vertical">

        <info.hoang8f.widget.FButton
            android:id="@+id/buttonA"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:onClick="buttonA"
            android:text=""
            android:textColor="@color/grey"
            fbutton:buttonColor="@color/white"
            fbutton:cornerRadius="10dp"
            fbutton:shadowColor="@color/grey" />

        <info.hoang8f.widget.FButton
            android:id="@+id/buttonB"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:onClick="buttonB"
            android:text=""
            android:textColor="@color/grey"
            fbutton:buttonColor="@color/white"
            fbutton:cornerRadius="10dp"
            fbutton:shadowColor="@color/grey" />


        <info.hoang8f.widget.FButton
            android:id="@+id/buttonC"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:onClick="buttonC"
            android:text=""
            android:textColor="@color/grey"
            fbutton:buttonColor="@color/white"
            fbutton:cornerRadius="10dp"
            fbutton:shadowColor="@color/grey" />

        <info.hoang8f.widget.FButton
            android:id="@+id/buttonD"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:onClick="buttonD"
            android:text=""
            android:textColor="@color/grey"
            fbutton:buttonColor="@color/white"
            fbutton:cornerRadius="10dp"
            fbutton:shadowColor="@color/grey" />

    </LinearLayout>


</LinearLayout>

Onde está o problema?

questionAnswers(2)

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