Crash SLComposeViewController initWithExtension

Number:rdar://35879620 Date Originated:12/06/17
Status:Open Resolved:No
Product:UIKit Product Version:11.1.1
Classification:Crash Reproducible:Sometimes
After sharing something using UIActivityViewController and extensions (we especially noticed this with Slack), the extension crashes our app in the following thred:

2  Social                         0x194a04dbc __66-[SLComposeViewController initWithExtension:requestedServiceType:]_block_invoke + 84
3  Foundation                     0x184103b04 __85-[NSExtension _completeRequestReturningItems:forExtensionContextWithUUID:completion:]_block_invoke + 108

We don't even use Social.framework anywhere in the app, so we also don't cause a crash by trying to use SLComposeViewController in iOS 11. We attached a crash report from Crashlytics as well. We did some research and this crash seems to appear for other developers as well. Take a look at the following examples:

We tried to share to items using UIActivityViewController: an instance of NSURL and a simple string.

Steps to Reproduce:
1. Share something using an extension (try Slack)
2. Press "Post" in extension's view controller
3. Extension crashes our app

11.1.1 (15B150), iPhone SE


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