DESCRIPTION OF PROBLEM Logs and data from our application indicate various errors that strongly suggest that our application is being launched in a state in which the device is likely locked. We are looking for guidance on how to identify, debug, reproduce, and fix these cases. Our application does not use any of the common mechanisms for background activity, such as Background App Refresh, Navigation, Audio, etc. Errors we get in our logs such as "authorization denied (code: 23)" when trying to access a file in our app's container on disk (a simple disk cache for data our application uses) strongly suggest that the device is operating in a state, such as being locked, where our application lacks the requisite permissions it would normally have during operation. Furthermore, attempts to access authentication information stored in the keychain also fails. We use kSecAttrAccessibleWhenUnlocked when accessing items we store in the keychain. We have investigated "Prewarming", as well as our notification extension that helps process incoming push notifications, but cannot find any way to recreate this behavior. Are there any steps Apple engineers can recommend to triage and debug this? Some additional questions that would help us: What are all of the symptoms that we can look for if prewarming escapes the intended execution context? What are all of the circumstances in which we would be unauthorized to access the app’s documents/file directories even if it works correctly in normal operation? STEPS TO REPRODUCE Unfortunately, we are unable to forcibly reproduce this behavior in our application, so we're looking for guidance on how we might simulate this behavior in Xcode / Instruments. Are there tools that Apple provides that would allow us to simulate certain behaviors like prewarming to verify our application's functionality? Are there other reasons our application might be launched while the device is locked? Are there other reasons we would receive security errors when accessing the keychain or disk that are unrelated to the device being locked?