Data not visible after resume the app / --env.uglify option

Hi

I have configured the pdf viewer on my app.when i run my app the pdf file was loaded.but if i switch the app to another app and then come back (resume) to the same app ,the loaded pdf content was not visible. Another thing i found , if i build the app with --env.uglify option the same thing is happening , even the app was not switch to another app.