Runtime crash

[syonip]

I followed instructions and getting crash when running:
App theme is defined in manifest as: android:theme="@style/Platform.AppCompat.Light"

Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
        at android.support.v7.app.AppCompatDelegateImplBase.onCreate(AppCompatDelegateImplBase.java:112)
        at android.support.v7.app.AppCompatDelegateImplV7.onCreate(AppCompatDelegateImplV7.java:148)
        at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:60)
        at com.tenmiles.helpstack.activities.HSActivityParent.onCreate(HSActivityParent.java:42)
        at com.tenmiles.helpstack.activities.HomeActivity.onCreate(HomeActivity.java:45)