com.rnfs.RNFSManager.mkdir: java.lang.Exception: Directory could not be created

https://github.com/itinance/react-native-fs

code

import RNFS from 'react-native-fs';RNFS.mkdir(RNFS.ExternalDirectoryPath + dir)

logcat

05-06 22:43:41.693  W/System.err: java.lang.Exception: Directory could not be created05-06 22:43:41.697  W/System.err:     at com.rnfs.RNFSManager.mkdir(RNFSManager.java:680)

This error occurs after compilation，

But it is normal when debugging，