This is using the Xcode organiser, right? Yes. hence the recommendation in TN3151 Choosing the right networking API. If you were starting from scratch I’d definitely recommend you use Network framework. Wow, somehow I missed the recommendation completely. Thanks a lot for pointing this out! I rewrote the web socket code to use the Network framework, everything seems to work fine, so after some internal testing we'll release it to the App Store and see how it goes. Thanks again!

Unfortunately, we have never seen these crashes ourselves, so all we have is crash reports from the App Store in Xcode. What surprises me a bit is "Role: Non UI" in all but one crash instance though the app does not use any background modes. We do use NSURLSessionWebSocketTask, though.

@DTS Engineer Thanks for taking a look. Here is a couple of full crash reports. 2025-03-18.crash 2025-07-21.crash