Question: I am trying out [Activity Transitions](https://developer.android.com/training/material/animations.html#Transitions) and when I paste below code in my values-21/styles.xml I get error: 

> 
> cannot resolve symbol '@transition/explode'
> 
> 
> 

```
<style name="BaseAppTheme" parent="android:Theme.Material">
  <!-- enable window content transitions -->
  <item name="android:windowContentTransitions">true</item>

  <!-- specify enter and exit transitions -->
  <item name="android:windowEnterTransition">@transition/explode</item>
  <item name="android:windowExitTransition">@transition/explode</item>

  <!-- specify shared element transitions -->
  <item name="android:windowSharedElementEnterTransition">
    @transition/change_image_transform</item>
  <item name="android:windowSharedElementExitTransition">
    @transition/change_image_transform</item>
</style>

```

Answer: 
Did you create a `res/transition/explode.xml` file with the following contents?

```
<transitionSet xmlns:android="http://schemas.android.com/apk/res/android">
    <explode />
</transitionSet>

```
Simplest Answer - Replace it with @android:transition/explode