The following classes could not be found: android.support.v7.internal.app.WindowDecorActionBar

What causes the following error in the layout preview in Android Studio?

Rendering Problems The following classes could not be found: - android.support.v7.internal.app.WindowDecorActionBar (Fix Build Path, Create Class) Tip: Try to build the project.

The Actionbar has been deprecated and replaced by Toolbar. That being said, you can do the following if you want to continue using Actionbar for now:

1. Open styles.xml in the values folder inside the res folder.
2. Add the word Base to the beginning of the theme name so that it reads "Base.Theme.AppCompat.Light.DarkActionBar"

I had the same issue today and this solution worked for me. FYI I am in Android Studio though, but hopefully,the solution is similar for Eclipse.

FYI here is a decent blog post on replacing the Actionbar with the Toolbar for when you are ready to do so: https://blog.xamarin.com/android-tips-hello-toolbar-goodbye-action-bar/

I think you must be depending on "com.android.support:appcompat-v7:23.1.1" in your module settings.

ActionBar has been deprecated.

Just change your dependencies from 'com.android.support:appcompat-v7:23.1.1' to 'com.android.support:appcompat-v7:23.0.1' in "build.gradle".

You can also change your style parent to "Theme.AppCompat.Light.NoActionBar".

Try to use the Toolbar instead of ActionBar.

This one works for me

Changing AppTheme parent in res/values/styles.xml resolved this problem. Replace

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
</style>

with

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
</style>

Or you can change API level 21 from list.

goto: res-->values-->styles(V21)-->

Code

<style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
    <item name="android:windowDrawsSystemBarBackgrounds">true</item>
    <item name="android:statusBarColor">@android:color/transparent</item>
</style>

select your theme as Apptheme.NoActionBar in preview. Because ActionBar is depricated, welcome back to ToolBar. NO need to change your dependencies in build.gradle(Module:app). from com.android.support:appcompat-v7:23.1.1 to com.android.support:appcompat-v7:23.0.1.

Hope this will help you!!!