Crashed: XPC API Misuse: Over-resume of a connection

Question

We have a crash in our iOS app reported by Crashlytics:

Device: iPhone 6+
iOS: 10.0.1

The stack trace is:

Crashed: XPC API Misuse: Over-resume of a connection.
0  libxpc.dylib                   0x18eb526b0 _xpc_api_misuse + 48
1  libxpc.dylib                   0x18eb526b0 _xpc_api_misuse + 48
2  libxpc.dylib                   0x18eb3ec08 xpc_connection_resume + 76
3  CFNetwork                      0x190138500 -[__NSURLBackgroundSession setupXPCConnection] + 292
4  CFNetwork                      0x190139260 -[__NSURLBackgroundSession ensureRemoteSession] + 64
5  libdispatch.dylib              0x18e8f5200 _dispatch_call_block_and_release + 24
6  libdispatch.dylib              0x18e8f51c0 _dispatch_client_callout + 16
7  libdispatch.dylib              0x18e903444 _dispatch_queue_serial_drain + 928
8  libdispatch.dylib              0x18e8f89a8 _dispatch_queue_invoke + 652
9  libdispatch.dylib              0x18e903940 _dispatch_queue_override_invoke + 360
10 libdispatch.dylib              0x18e90538c _dispatch_root_queue_drain + 572
11 libdispatch.dylib              0x18e9050ec _dispatch_worker_thread3 + 124
12 libsystem_pthread.dylib        0x18eafd2c8 _pthread_wqthread + 1288
13 libsystem_pthread.dylib        0x18eafcdb4 start_wqthread + 4

Any idea about how to reproduce it?
Any idea about what can create the crash?

Sonnysonobuoy

I have the same problem. Can only see it in iOS 10. I suspect that the issue is somewhere in Crashlytics itself as it is the only part of my app that uses networking. – Aphrodisia

What version of the Crashlytics SDK are you on? (we saw this on 3.8.1, under iOS 10.0.2) – Wiry

3.8.2 right now. Maybe the day of the crash it was 3.8.1. So, it sounds like a Crashlytics problem? – Sonnysonobuoy

Yep, it sounds like! See mattie's reply at the bottom of this Apple thread: forums.developer.apple.com/thread/20724 – Wiry

Have this crash on Crashlytics 3.8.2 – Raphael

Answer 1

Crashlytics Insights

Heads Up!

XPC API Misuse by a NSURLSession

Details:

The stack trace indicates an issue with usage of the XPC API. It looks like NSURLSession background uploads is causing issues with XPC. Since XPC is not available to third-party developers on iOS, this is probably an Apple bug. If this affects your ability to use background uploads, we recommend filing a radar with Apple and working around background uploads, if possible.

Resources:

Apple Developer Forums: XPC API Misuse - iOS 9 crash

Answers Changelog, version 1.3.3

Grillparzer