Note: This applies to PDF Viewer 2.1, which has been released on December 15, 2017.
In iOS 11, Apple introduced a new Files app to manage both local and remote files on iOS, supporting iCloud, Box Dropbox and many other cloud storage providers.
Before that, each app which wanted to support e.g. Dropbox, had to manually implement all logic required to talk to Dropbox servers. Now, every app which uses the new document browser automatically supports all providers supported there.
Know that all your files are still there. The new document browser has a different folder hierarchy as it allows to access all files on your iPad now.
Since this control is still quite new, some vendors haven't updated their app yet. They still show up in the list, but tapping opens a controller modally with an outdated design (e.g. Microsoft OneDrive). These companies will need to update their integration before it can be used with PDF Viewer.
As a brand new system control, Apple's Document Browser still has a few bugs. We reported all of them to Apple and expect that it will improve in upcoming iOS releases:
The screen is blank, shows a "proxy error", "Content Unavailable" or some entries such as “On My iPhone" are missing.
This is a sporadic issue that can be resolved most of the times by restarting the app or restarting your iPhone or iPad. If specific entries are missing, they might just have been disabled, press "Edit" and enable all sources that are interesting to you.
You can help with collecting a sysdiagnose when this is happening.
Blank Screen instead of displaying any UI
Sometimes the control fails to load. The system log shows a "Unable to initialize remote proxy for extension. The connection was interrupted." message. Killing and restarting the app fixes the issue. rdar://35643182
Icons overlay with the status bar
Sometimes this happens when showing/hiding our Viewer UI and then going back to the Document Browser View. This can be fixed by simply opening another PDF or restarting the app. radar://39276662
Interactive pop gesture doesn’t work in UIDocumentBrowserViewController
The back navigation gesture doesn't work. It's also broken in Keynote.app, but it works just fine in Files.app. rdar://35666735
3D Touch Preview doesn’t work in UIDocumentBrowserViewController
However, it works in Files.app. rdar://35666733
Indexed Search no longer works
While PDF Viewer uses Core Spotlight to index documents, the document browser is not yet using this information, so searching for document content is not yet functional. rdar://33004145
The Document Action Toolbar is gone
Before PDF Viewer 2.1, a contextual toolbar offered actions when files/folders were selected. While we cannot replicate this feature in the new document browser, you can long-press on a file to open a menu with actions. This also starts a drag and drop session, but will eventually show the menu. rdar://33004056
Moving Files is difficult
The new document browser relies on drag and drop for moving documents, unlike the view-based approach we offered in earlier versions of PDF Viewer. This is often enough, but can make navigating deep folder hierarchies difficult. rdar://33004045
The background in 'Recents' looks broken
Looking at the ‘Recents’ tab on an iPhone X shows a background gradient from white to gray and then the grey background suddenly stops resulting in a strange looking hard border that looks as if the content somehow only rendered half way and there should be something there. rdar://35696588
Huge gap at end of scroll view on iPhone X
When looking at a folder in UIDocumentBrowserViewController on an iPhone X, after the last file you can continue to scroll about half of a screen size. rdar://35696637
List cannot be fully scrolled down
Certain configurations might cause the bottom bar to incorrectly overlap the file list, so that tapping the last item is difficult. This is a bug that we will report to Apple as soon as we can track it reliably.
Moving files actually creates a copy
This is an implementation detail of both Apple and 3rd-party file providers, moving sometimes doesn't what you expect it to do.
Browser hides info about number of items and available space
When looking at an iCloud Drive folder in a UIDocumentBrowserViewController, there is information about the number of files in a folder and the available space on iCloud, however this line of text is hidden initially even though there are only a few files and this info could be displayed right away. rdar://35696675
External linked PDF files cannot be opened
It is currently not possible to request access to linked external files, so an action that opens an external linked file currently does not work, unless the file is stored in local storage "On My iPhone". rdar://36129256
There are also a few issues that affect how convenient we can build features, such as rdar://33101847, theming issues (rdar://33004109), allowing us to customize the new document cell (rdar://33004019), making the startup experience nicer (rdar://33003975), improving the buttons offered in the toolbar (rdar://33003963) or changing the bottom tab bar (rdar://33003809)
Issues with Cloud Storage Providers
Some files can't be downloaded; they are missing, or get corrupted when using cloud storage providers. Please refer to our troubleshooting guide for how to work around them.