Maybe the file is still downloading in the background by nsurlsessiond, but how can I track the download progress in my app once it goes to the background and later comes back to the foreground? My app shows an error banner when the download stops, but this happens every time after the app goes to the background. I assume this is because the download is no longer happening in the app itself. What should I do? and when it comes to the error part i am doing session.invalidateandcancel to keep the session fresh for the next download task will this effect the background task by the nsurlsessiond