Android FragmentTabHost Must call setup() that takes a Context and FragmentManager

Question

Probably it's a stupid error but I can't figure out what I'm doing wrong.

I have a basic xml with a FragmentTabHost and a coordinatorLayout (Even removing the coordinator the error persist).

This is the xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="...">

    <android.support.v4.app.FragmentTabHost
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@android:id/tabhost"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical" >

            <TabWidget
                android:id="@android:id/tabs"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"/>

            <FrameLayout
                android:id="@android:id/tabcontent"
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1" />
        </LinearLayout>

    </android.support.v4.app.FragmentTabHost>

        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="16dp"
            android:clickable="true"
            app:layout_anchor="@id/activity_main"
            app:layout_anchorGravity="bottom|right|end" />

</android.support.design.widget.CoordinatorLayout>

Then I set up the FragmentTabHost in my java code like the following:

public class MainActivity extends AppCompatActivity {

    private FragmentTabHost mTabHost;

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

        mTabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
        mTabHost.setup(this, getSupportFragmentManager(), android.R.id.tabcontent); //tried both those
        //mTabHost.setup(this, getSupportFragmentManager()); //tried both those

        mTabHost.addTab(mTabHost.newTabSpec("cerca").setIndicator("Cerca"),
                SearchFragment.class, null);
        mTabHost.addTab(mTabHost.newTabSpec("favoriti").setIndicator("Favoriti"),
                FavoriteFragment.class, null);

    }
}

I think this is pretty much a simple code, but I don't get why when compiling or when looking my xml I get this error:

 java.lang.IllegalStateException: Must call setup() that takes a Context and FragmentManager
    at android.support.v4.app.FragmentTabHost.setup(FragmentTabHost.java:188)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.setupTabHost(RenderSessionImpl.java:1191)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.postInflateProcess(RenderSessionImpl.java:972)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.postInflateProcess(RenderSessionImpl.java:1048)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.postInflateProcess(RenderSessionImpl.java:1048)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:336)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:429)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:389)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:548)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:533)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:966)
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:533)
    at com.android.tools.idea.rendering.RenderTask.lambda$inflate$53(RenderTask.java:659)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

I cleaned, I recompiled, I changed my setup method to be with or without the 3rd param. I don't kow what to do, any idea?