iOS AWSS3 TransferUtility fails to upload zip file

Question

I'm trying to upload a zip file and facing this issues. When I try with the older version PutObject methods, the file is getting uploaded successfully but with the latest iOS sdk I am unable to upload file.

_expression = [AWSS3TransferUtilityUploadExpression new];
_expression.progressBlock = ^(AWSS3TransferUtilityTask task, NSProgress progress) {
    dispatch_async(dispatch_get_main_queue(), ^{
        // Do something e.g. Update a progress bar.

        NSLog(@"Upload Progress '%%'%lld",((task.progress.completedUnitCount*100)/(task.progress.totalUnitCount)));
    });
};

_completionHandler = ^(AWSS3TransferUtilityUploadTask task, NSError error) {
    dispatch_async(dispatch_get_main_queue(), ^{
        // Do something e.g. Alert a user for transfer completion.
        // On failed uploads, `error` contains the error object.

        if (!error) {
            NSLog(@"task completed");
        }
        else {
            NSLog(@"task completed with Error\n\n %@",error);
        }
    });
};

_transferUtility = [AWSS3TransferUtility defaultS3TransferUtility];

[[_transferUtility uploadFile:_uploadFileURL
                      bucket:_bucketName
                         key:_key
                 contentType:@"application/zip"
                  expression:_expression
            completionHander:_completionHandler] continueWithBlock:^id(AWSTask *task) {
    if (task.error) {
        NSLog(@"Error: %@", task.error);
    }
    if (task.exception) {
        NSLog(@"Exception: %@", task.exception);
    }
    if (task.result) {
        AWSS3TransferUtilityUploadTask *uploadTask = task.result;

        // Do something with uploadTask.
    }

    return nil;
}];

And getting following error:

Error Domain=com.amazonaws.AWSS3TransferUtilityErrorDomain Code=2 "(null)" UserInfo={Server=AmazonS3, Transfer-Encoding=Identity, Connection=close, Content-Type=application/xml, Date=Fri, 07 Oct 2016 08:10:37 GMT, x-amz-request-id=F481248FB3DAD978, x-amz-id-2=iWWS/ZrHxtAeIzMD5PmgvE52azggJYumGHNp6aLWB9NgeIfR56yty66n/JfP4SQ/behSLKChEfE=}