In line comments break react-native 56+, as shown below. Removing "This comment breaks the app" allows the app to run. Comments on lines by themselves seem to be ok.

exportdefaultclassAppextendsComponent<Props>{render(){return(<Viewstyle={styles.container}>{/* This comment is ok */}<Textstyle={styles.welcome}>Welcome to React Native!</Text>{/* This comment breaks the app */}<Textstyle={styles.instructions}>To get started, edit App.js</Text><Textstyle={styles.instructions}>{instructions}</Text></View>);}}