Quickblox: an issue in deleting content item (pict

I am having a weird issue when I try to delete a content item (picture blob item for the user), stored as PNG picture file in the back-end database.

The delete proceeds without errors, but gives "422 Unprocessable Entity". What does this mean? The status of the content item seems to be OK and ready when checked in Quickblox admin panel.

I have uploaded the content with following API call:

[QBContent TUploadFile:imageData fileName:@"profile.png" contentType:@"image/png" isPublic:YES delegate:self];

I am trying to delete the object with following API call:

[QBContent deleteBlobWithID:blobID delegate:self];

QB logs:

Performing async request: 
DELETE http://api.quickblox.com/blobs/91049.xml
headers:{
    "QB-SDK" = "iOS 1.8";
    "Qb-Token" = b9e3d1cc708c8444070544df8c642ad194509e67;
    "QuickBlox-REST-API-Version" = "0.1.1";
}
parameters:
2013-12-12 14:33:52.328 QBTestApp[21095:6b73] Request finished, response:
headers:{
    "Access-Control-Allow-Origin" = "*";
    "Cache-Control" = "no-cache";
    Connection = "keep-alive";
    "Content-Length" = 49;
    "Content-Type" = "application/xml; charset=utf-8";
    Date = "Thu, 12 Dec 2013 13:33:58 GMT";
    "QB-Token-ExpirationDate" = "2013-12-12 15:32:22 UTC";
    "QuickBlox-REST-API-Version" = "0.1.1";
    Server = "nginx/1.0.15";
    Status = "422 Unprocessable Entity";
    "X-Rack-Cache" = "invalidate, pass";
    "X-Request-Id" = 3f235134e5aa0bd012ef78e54cddc164;
    "X-Runtime" = "0.039680";
    "X-UA-Compatible" = "IE=Edge,chrome=1";
}
body:
error:
<?xml version="1.0" encoding="UTF-8"?>
<errors/>

Any ideas what I might be doing wrong here? Thanks (again) in advance! :-)

The feeling that you are trying to delete a blob file that does not exisе. Please make sure that you are trying to delete a blob file after the upload and the creation process is completed(calling completedWithResult: with successful result).

If I could see the order of method calls TUploadFile: and deleteBlobWithID: in the code, I could help you more quickly.