Ok, thank you very much. However, the sysdiagnose log is unlikely to be available at this time :( I will pay attention to the feedback from users.

At first I also thought it was a multi-threaded concurrency problem, but the user also had the same crash problem in other places (such as object model to JSON string) :(

Thanks for your reply. The log file is from Settings->Privacy->Analytics Data export ips file from user's iPad Mini 2. Is there any others log can help to analy this problem? Is possible the user’s iPad hardware disk or memory is broken to cause this problem?