Here is the crash report, thank you @eskimo 2022-11-11, 08-14.crash

could anyone explain how to find the cause from my own code from this? as I could not find connections. Or I missed some configurations for the crash report... thanks.

Thank you @eskimo! Unfortunately, I could not reproduce it by triggering a sysdiagnose log, could you give me a hint on how to involve a sysdiagnose log? Yesterday I got another crash report due to probably the same reason but with a little difference in the backtrace, the report is attached. Is my understanding correct that I should generally use DispatchQueue.main.async {} for all the possible background threads/tasks which update UI? 2022-12-3.crash

Thanks, @eskimo for the good hint. I found it was because I tried to access items in coredata after actually deleting them. I would like to move the photos that had been downloaded before to the top of the list. I implemented this with deleting the downloaded photos and re-downloading, then boom... Now I only change the date property for the photo then sort by date, seems ok now.

@Rumio, I haven't received the same crash as this again, the root cause is still not clear to me. An extra thing I did after the last crash was to add DispatchQueue.main.async {} to all potential codes which update UI outside of the main thread, so the root fault will still be latent until I get another same crash...or what was happening in 'auto layout' regarding this crash can be figured out...