I had the same issue as you.
The issue is with something you have in your style.
Try this out:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="My_Theme">
<item name="android:windowTitleSize">35dp</item>
<item name="android:windowTitleBackgroundStyle">@android:color/black</item>
</style>
</resources>