I'm building an app that renders PDFs in SwiftUI through PDFKit.

Users can choose the PDF which they want to render. It's done through .fileImporter which returns a URL.

The URL works fine and I can render the PDF using the provided URL (I have to call url.startAccessingSecurityScopedResource() in order to render it; without calling that method, it does not render).

The trick is when I close the app, open it, and try to render a PDF using the URL that I obtained in a previous session, it just does not work, it renders empty string. I have to re-upload the file again (it generates absolutely the same URL) in order to make it render correctly.

What am I missing? I'm asking this question because unfortunately XCode does not give any any errors/warnings and I literally have no idea what to dig at least.

Not sure if its your problem, but I had problems with a Mac app. I could display a file selection dialog and the user could select a file and I could read it fine. If I stored the url and tried to open the file next time my app ran, I could not read the file. I didn't crash, just got nothing back. To make this work, I had to turn off sandboxing for the app. The sandboxing restrictions would only let me open files selected by the user directly. Any url I tried to access that was not selected by the user would fail.

Never found a way round it, so just deleted the Sandbox options from my app and run without sandboxing.

Steve