Error when I create PDFDocument with filePath from other app's local folder

[hoangtm12]

When I run "let document = PDFDocument(url: filePath)" on Demo app, if my file is into Demo app's folder, it is ok, but if my file is into other app's folder such as Demo2222 app --> It's error, document is nil. I get filePath, fileName by UIDocumentPickerViewController, and e.thg is ok.
Such as:

• FilePath Demo app:
  file:///private/var/mobile/Containers/Data/Application/D3EB4157-93C7-48DB-9515-F4993E1FA172/Documents/aaa.pdf ----> OK
• FilePath Demo222 app:
  file:///private/var/mobile/Containers/Data/Application/D3EB4157-93C7-48DB-9515-F4993E1FA1224/Documents/aaa.pdf --> NOT OK, document is nil.
  So, how can I create a PDFDocument from other app's local folder