Hi,
Since iOS8, the NSUrlSession in background mode does not call this delegate method if the server does not respond.
-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
The download remains idle undefinitely.
This delegate is called on iOS7 with an error when the server does not respond.
I have the same problem when I set the device to plane mode during a download. It fails on iOS7 and stays idle whithout failing on iOS8+.
Do you have insight on this?
Thanks,