Ionic native file opener 2 error class not found

I receive error when trying to open a file

.ts

open(){
  this.platform.ready().then(() => {
    this.fileOpener.open(this.entry.nativeURL, this.attachment.mime).then(() => {
      console.log('file opened')
    }, err => {
      console.log('error open file: ', err)
    });
  });
}

this.entry.nativeURL is the download result using File Transfer
nativeURL: file:///storage/emulated/0/Download/someFile.docx

this.fileTransfer.download(url, this.storageDirectory + this.attachment.fileName, trustAllHosts).then((entry) => {
    console.log('entry: ', entry);
    this.entry = entry;
}

this.attachment.mime is the information gotten using ng2-file-upload
mime: application/vnd.openxmlformats-officedocument.wordprocessingml.document

its working… the problem occurred because i was running the app live --livereload

Hi,

I have the same problem always… if i running de app with ionic cordova build android, or android --prod or android --prod --release

Somebody can help me? im using old ionic version because the app its very old

cli packages: (---)
    @ionic/cli-utils  : 1.19.2
    ionic (Ionic CLI) : 3.20.0

global packages:
    cordova (Cordova CLI) : 8.0.0

local packages:
    @ionic/app-scripts : 3.2.1
    Cordova Platforms  : android 7.0.0
    Ionic Framework    : ionic-angular 3.9.2

System:
    Android SDK Tools : 26.1.1
    Node              : v8.11.2
    npm               : 6.4.1 
    OS                : Windows 7

Environment Variables:
    ANDROID_HOME : c:\android

Misc:
    backend : pro

Thanks in advanced