removeFromSuperview does not work

Question

I've this piece of code that try to feed an array from a web-service. If it fails, an error message appears, with the possibility to tap on it to retry. But when I tap on it, the error message doesn't disappear, and the spinner doesn't re-appear.

-(void)Load_Commandes{
    if(LIB_Error)
    {
        [LIB_Error removeFromSuperview];
        LIB_Error = nil;
    }

    TABLE_Commandes.hidden = YES;
    LIB_Chargement.hidden = NO;
    spinner.hidden = NO;

    [spinner startAnimating];

    tab_Cdes = [self Init_Tableau];

    spinner.hidden = YES;
    LIB_Chargement.hidden = YES;

    if(tab_Cdes != nil)
    {
        TABLE_Commandes.hidden = NO;
        [TABLE_Commandes reloadData];
    }
    else
    {
        LIB_Error = [[UILabel alloc] initWithFrame:self.view.frame];
        [LIB_Error setTextColor:[UIColor grayColor]];
        [LIB_Error setBackgroundColor:[UIColor clearColor]];
        [LIB_Error setTextAlignment:NSTextAlignmentCenter];
        [LIB_Error setText:@"Erreur de chargement. \nToucher pour réessayer."];
        [LIB_Error setNumberOfLines:2];
        UITapGestureRecognizer* gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(Load_Commandes)];
        [LIB_Error addGestureRecognizer:gesture];
        LIB_Error.userInteractionEnabled = YES;

        [self.view addSubview:LIB_Error];
    }
}

Here is the code I use to call the web-service, in [self Init_Tableau].

NSString *str=[NSString stringWithFormat:URL_ORDERS];
NSURL *url=[NSURL URLWithString:str];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:5.0];
NSData *returnData = [NSURLConnection sendSynchronousRequest: request returningResponse:&response error: &error];

Thanks you for your help, because I'll become crazy! ^^

UPDATE : I tried by a lot of different ways. But it seems to be impossible to do. Whatever I do, the visual changes are applied only when all treatments are done.

---

Here is the code of Init_Tableau.

 -(NSArray*)Init_Tableau
    {
        NSMutableArray* a = [NSMutableArray array];

        Reachability *networkReachability = [Reachability reachabilityForInternetConnection];
        NetworkStatus networkStatus = [networkReachability currentReachabilityStatus];
        if (networkStatus == NotReachable) {
            NSLog(@"Erreur de chargement 1");
            //return nil;
        }


        NSURLResponse* response;
        NSError* error;

        NSString *str=[NSString stringWithFormat:URL_ORDERS];
        NSURL *url=[NSURL URLWithString:str];
        NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:5.0];
        NSData *returnData = [NSURLConnection sendSynchronousRequest: request returningResponse:&response error: &error];
        NSString *responseBody = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
        if(error)
        {
            NSLog(@"Erreur de chargement 2");
            return nil;
        }

        NSError *e = nil;
        NSArray* resultList = [NSJSONSerialization JSONObjectWithData:returnData options:NSJSONReadingMutableContainers error:&e];

        for(NSDictionary* dico in resultList){
            Entete* cde = [[Entete alloc] init];
            cde.ncde = [dico objectForKey:NCDE];
            cde.nomf = [dico objectForKey:NOMF];
            cde.noml = [dico objectForKey:NOML];
            cde.prenomf = [dico objectForKey:PRENOMF];
            cde.prenoml = [dico objectForKey:PRENOML];
            cde.adresse1f = [dico objectForKey:ADRESSE1F];
            cde.adresse1l = [dico objectForKey:ADRESSE1L];
            cde.adresse2f = [dico objectForKey:ADRESSE2F];
            cde.adresse2l = [dico objectForKey:ADRESSE2L];
            cde.cpf = [dico objectForKey:CPF];
            cde.cpl = [dico objectForKey:CPL];
            cde.villef = [dico objectForKey:VILLEF];
            cde.villel = [dico objectForKey:VILLEL];
            cde.phonef = [dico objectForKey:PHONEF];
            cde.phonel = [dico objectForKey:PHONEL];
            cde.societef = [dico objectForKey:SOCIETEF];
            cde.societel = [dico objectForKey:SOCIETEL];
            cde.etatCde = [dico objectForKey:ETATCDE];
            cde.moyenPaiement = [dico objectForKey:MOYENPAIEMENT];
            cde.fdp = [dico objectForKey:FDP];
            cde.mnt = [[dico objectForKey:MNTCDE] floatValue];
            [a addObject:cde];
        }

        return [NSArray arrayWithArray:a];
    }