Rendering problem the following class could not be found – android.support.v7.widget.appcompattextview

I'm new to Android studio. My project is running and executing, but every time I click activity_ When using main.xml, you will see an error that I don't understand. The error is

  Rendering Problems The following classes Could not be found:
- android.support.v7.widget.AppCompatTextView (Fix Build Path, Edit XML, Create Class)

My activity_ Main.xml is:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="fill_parent"     
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity"
android:background="#5b9bd5">



<ImageButton
    android:id="@+id/regiterbutton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/registerbutton"

    android:layout_marginBottom="67dp"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true" />

<ImageButton
    android:id="@+id/loginbutton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/loginbutton"

    android:layout_above="@+id/regiterbutton"
    android:layout_alignLeft="@+id/regiterbutton"
    android:layout_alignStart="@+id/regiterbutton"
    android:layout_marginBottom="50dp" />
</RelativeLayout>

My androidmanifest.xml is:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.jawadrauf.ratingapp" >

<uses-sdk
    android:minSdkVersion="9"
    android:targetSdkVersion="16"
    tools:overrideLibrary="com.facebook" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>
<!-- Connect to Internet Permissions -->
<uses-permission android:name="android.permission.INTERNET"/>
</manifest>

My build.gradle is:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 17
    buildToolsVersion '19.1.0'

defaultConfig {
    applicationId "com.example.jawadrauf.ratingapp"
    minSdkVersion 8
    targetSdkVersion 19
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt')
        ,        'proguard-rules.pro'
      }
    }
  }

 repositories {
 // You can also use jcenter if you prefer
 mavenCentral()
  }
 dependencies {
 compile fileTree(dir: 'libs', include: ['*.jar'])
 compile 'com.facebook.android:facebook-android-sdk:4.5.0'
 compile 'com.android.support:appcompat-v7:20.0.0'

 }

resolvent:

Appcompattextview is added in appcompat-v7: 22.1.0, and the latest version of appcompat-v7 is 24.0.0. Your gradle file uses a very old version 20.0.0

You must update the gradle file with the following command

compile 'com.android.support:appcompat-v7:24.0.0'

And ensure that all updates have been installed in SKD manager, including the latest version of the support library