Afnetworking: NSURLSession returns nil upload task in background

[erbenmo]

Hi,

I had an assertion error in AFN in AFURLSessionManager.m

• (void)setDelegate:(AFURLSessionManagerTaskDelegate *)delegate
  forTask:(NSURLSessionTask *)task;
  it is complaining that the task is nil.

which is called by

• (NSURLSessionUploadTask *)uploadTaskWithRequest:(NSURLRequest *)request
  fromFile:(NSURL *)fileURL
  progress:(NSProgress * __autoreleasing *)progress
  completionHandler:(void (^)(NSURLResponse *response, id responseObject, NSError *error))completionHandler;

It seems [self.session uploadTaskWithRequest:request fromFile:fileURL] is returning a nil.

All of the above error happened in background and it is not happening every time.
I checked that self.session is not nil. request seems valid and the file exists at fileURL.

Has anyone had this issue before?

[JayZhao]

I found that downloadTaskWithRequest also returns nil, I have no idea how it happened.

[kolyuchiy]

It looks like this is a bug in iOS. More info here: https://devforums.apple.com/message/926113#926113

[yechunjun]

I also found this issue that downloadTaskWithRequest returns nil. Anybody knows how to fix?

[donholly]

Anyone have any update on this by chance? Seeing the same thing :(

[kolyuchiy]

I tried to fix it by making more attempts to create the task after nil has been returned (https://github.com/denivip/AFNetworking/commit/4872bf2a3ee0d4c8dc5570673b7db1958a04be17). This hasn't fixed the problem completely, but now we get much less of these errors (on the order of 10-100 times less).

[mattt]

Proposed workaround in #2074. Please continue discussion on that thread.

[aCatDream]

Hi

Today i have a similar bug : after 10 or 20 background downloading, [self.session downloadTaskWithRequest:request] return always nil.

In this case, i modify downloadTaskWithRequest for return nil and the application re-init AFURLSessionManager.
This hack work !

So, when downloadTask is nil, i sugest to re-init the NSURLSession instance before ask for a new download task.

I hope this help you.

[donholly]

I've noticed this seems to be cleaned up in iOS 8. Is anyone else noticing the same?