Error in granting access to baasbox document objects which was created through ios code in a particular collection

Error is: Error Domain=com.baasbox.error Code=-22222 "id (null) no found" UserInfo=0x9daa3a0 {BaasBox_API_version=( "0.9.1" ), iOS SDK Version=0.9.0, NSLocalizedDescription=id (null) no found}

Code i used:

DeliveryTax *p = [[DeliveryTax alloc] init];

p.delTax = @"30";

[p saveObjectWithCompletion:^(DeliveryTax *del, NSError *error) {

[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];

if (error == nil) {
    NSLog(@"Delivery tax in saving is %@", del.delTax);
    [del grantAccessToRole:kAclRegisteredRole                                                                ofType:kAclReadPermission completion:^(DeliveryTax *post, NSError *error) {

        if (error == nil) {                                                                      NSLog(@"permission granted");

        } 
        else {
           NSLog(@"error in granting permission");
        }

    }];
} 
else {

        UIAlertView *alert = [[UIAlertView alloc]    initWithTitle:NSLocalizedString(@"ERROR", nil)
                                                       message:NSLocalizedString(@"ERROR_SEND_ORDER", nil)
                                                       delegate:nil
                                              cancelButtonTitle:@"OK"
                                              otherButtonTitles:nil, nil];
        [alert show];

}
}];