Blank white screen on UIDocumentBrowserViewController: Unable to initialize remote proxy for extension. The connection was interrupted.

Number:rdar://35643182 Date Originated:20-Nov-2017 11:02 AM
Status:Open Resolved:
Product:iOS + SDK Product Version:iOS 11.2b3
Classification:Serious Bug Reproducible:Sometimes
Sometimes UIDocumentBrowserViewController fails to load, leaving the app with a blank white screen. This seems to be a regression in iOS 11.2 b, at least I didn’t notice it before. The console prints this error message:

[DocumentManager] Failed to get the remote browser View Controller with error (Error Domain=NSExtensionErrorDomain Code=-1 "Unable to initialize remote proxy for extension. The connection was interrupted." UserInfo={NSLocalizedDescription=Unable to initialize remote proxy for extension. The connection was interrupted.})

Steps to Reproduce:
Start a UIDocumentBrowser-based app, for example PDF Viewer 2.1 or later (In beta current, see

Expected Results:
It always loads and displays the document browser

Actual Results:
Sometimes it fails and displays a blank white screen (often enough on my iPhone 6S that it made me file this bug report)

iOS 11.2b3

Other people report similar issues, for example see Radar #35587230. You can try this yourself via the public TestFlight beta of . 

Radar Reviewer notes:
This can be reproduced with any sample project featuring the UIDocumentBrowser as well so I did not include yet another sample. If Apple has no internal sample, there are many open source samples available like


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