Transfer file does not work in Android release build but works in debug build

Hey! i just finish my application, so i build release build with a private key to publish it in playstore, my problem is :

  • i have function :

    var pathdevices = this.file.externalRootDirectory;
    pathdevices = pathdevices + “/ProSave/” +namefile;, pathdevices, true).then((entry) => {
      cordova.plugins.MediaScannerPlugin.scanFile(pathdevices,function () {
        this.showAlert('Thank you','Your download is complete');
      }, (error) => {
        this.showAlert('Download failed','The download was unable to complete. please try again 
          later, or check permission storage is enable');


this function work perfectly debug build it save the file in the floder " ProSave " in my devices but when release build it does not work i have no error.
i have been searching 2 days but no solution please if someone here has been work with this plugin “@ionic-native/file-transfer” with release build please help me for that.
Thanks you all.