Thank you for the reply, but according to the requirements on this link https://developer.apple.com/cn/app-store/submitting/, starting from April 2026, apps uploaded to App Store Connect must use iOS 26 SDK, which means Xcode 26 is also required. This seems contradictory to resolving the current issue. Could you provide the specific reason for the aforementioned problem? Why could the ipa compiled with Xcode 26 a week ago be installed, run, and used on an iPhone 6 12.5.8?

Thank you for the reply, but according to the requirements on this link https://developer.apple.com/cn/app-store/submitting/,starting from April 2026, apps uploaded to App Store Connect must use iOS 26 SDK, which means Xcode 26 is also required. This seems contradictory to resolving the current issue. Could you provide the specific reason for the aforementioned problem? Why could the ipa compiled with Xcode 26 a week ago be installed, run, and used on an iPhone 6?

Thank you for your reply, as the file corresponding to structure A in the SDK is not included in the SDK, which means it is not exposed to the outer layer. Therefore, there were no conflicts or warnings generated. Since iOS 7, this code has existed and ran consistently well, until the problem was exposed in iOS 18 beat 1. Therefore, we are considering whether iOS 18 has stricter handling of operating memory. We want to try to find a more specific cause of the error.

Your understanding is correct, and we believe that this code design is also inappropriate, so we have made corresponding adjustments. We just want to understand more clearly the cause of the error to avoid this situation from happening again in future development. Because before iOS 18 beat 1, there was no such random crash, and its crash scenario could occur in any scenario during app runtime.