Layout is just blank?

Question

I have restarted Android Studio, I have invalidated caches, I have Synced many times.. Nothing seems to work at all. Is there a problem with my Theme or my SDK?

It still shows blank on my preview. I am on Android 3.2.0-beta04 and my gradle version is 4.6. Please tell me if I need to add more code or information to this question.

build.gradle

apply plugin: 'com.android.application'

android {
compileSdkVersion 23
defaultConfig {
    applicationId "com.example.NAME.calculatorv2"
    minSdkVersion 15
    targetSdkVersion 23
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:23.4.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.2'
implementation 'com.android.support:design:23.4.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main"
    tools:context=".MainActivity">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@color/lightPureBlue">

        <TextView
            android:id="@+id/result_id"
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            android:gravity="right|center_vertical"
            android:hint="@string/base"
            android:textSize="30sp" />
    </RelativeLayout>


<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:background="@color/pureBlue">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:layout_gravity="center"
        android:gravity="center"
        android:paddingTop="10dp">

        <Button
            android:id="@+id/four"
            style="?android:attr/borderlessButtonStyle"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="@+string/four"
            android:textSize="30sp" />

        <Button
            android:id="@+id/five"
            style="?android:attr/borderlessButtonStyle"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="@+string/five"
            android:textSize="30sp" />

        <Button
            android:id="@+id/six"
            style="?android:attr/borderlessButtonStyle"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="@+string/six"
            android:textSize="30sp" />

        <Button
            android:id="@+id/subtract"
            style="?android:attr/borderlessButtonStyle"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="@+string/subtract"
            android:textSize="30sp" />

    </LinearLayout>
</RelativeLayout>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@color/pureBlue">

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal"
            android:layout_gravity="center"
            android:gravity="center"
            android:paddingTop="10dp">

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/one"
                android:textSize="30sp"
                android:text="@+string/one"
                style="?android:attr/borderlessButtonStyle"/>

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/two"
                android:textSize="30sp"
                android:text="@+string/two"
                style="?android:attr/borderlessButtonStyle"/>

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/three"
                android:textSize="30sp"
                android:text="@+string/three"
                style="?android:attr/borderlessButtonStyle"/>

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/mul"
                android:textSize="30sp"
                android:text="@+string/mul"
                style="?android:attr/borderlessButtonStyle"/>

        </LinearLayout>
    </RelativeLayout>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@color/pureBlue">

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal"
            android:layout_gravity="center"
            android:gravity="center"
            android:paddingTop="10dp">

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/zero"
                android:textSize="30sp"
                android:text="@+string/zero"
                style="?android:attr/borderlessButtonStyle"/>

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/clear"
                android:textSize="30sp"
                android:text="@+string/clear"
                style="?android:attr/borderlessButtonStyle"/>

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/equal"
                android:textSize="30sp"
                android:text="@+string/equal"
                style="?android:attr/borderlessButtonStyle"/>

            <Button
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:id="@+id/div"
                android:textSize="30sp"
                android:text="@+string/div"
                style="?android:attr/borderlessButtonStyle"/>

        </LinearLayout>



    </RelativeLayout>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:gravity="center"
    android:orientation="horizontal"
    android:paddingTop="10dp">

    <Button
        android:id="@+id/seven"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:text="@+string/seven"
        android:textSize="30sp" />

    <Button
        android:id="@+id/eight"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:text="@+string/eight"
        android:textSize="30sp" />

    <Button
        android:id="@+id/nine"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:text="@+string/nine"
        android:textSize="30sp" />

    <Button
        android:id="@+id/add"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:text="@+string/add"
        android:textSize="30sp" />

</LinearLayout>

Answer 1

I recently had similar problem. What helped me was changing the app theme. In your case it seems to be "NoActionBar". Try changing it to Material or Light.

Here is an animation of the procedure