If PDF Reader stops responding, make sure the latest iOS version is in use on your device and restart your device to see if the issue remains unsolved.

As a temporary solution, try the following steps:

Use Files App 

Apple's Files app is a place where you can browse and manage all your files in one place.

1. Launch the Files app (iOS 11 or later)
2. On My iPad
3. Find out the PDF Reader folder
4. Access or backup files to Cloud

Updated February 14, 2020 07:52