NSNotification used between two controllers is crashing
<p>i am using following code </p>

<p>First.m:</p>

<pre><code>[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(registerTok) name:@"registerTok" object:nil];  

[Second serviceCall:[NSString stringWithFormat:@"%@%@",BASEURL, USER_LOGIN] withParameter:parameters ofType:USER_SIGNIN];
</code></pre>

<p>Second.m:</p>

<pre><code>+(void)serviceCall:(NSString*)url withParameter:(NSDictionary*)parameter ofType:(int)type{

AFHTTPRequestOperationManager *manager = [[AFHTTPRequestOperationManager alloc] initWithBaseURL:[NSURL URLWithString:url]];  
        --------------line1------------------  
        [manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];  
        manager.responseSerializer = [AFJSONResponseSerializer serializer];  
        manager.requestSerializer = [AFHTTPRequestSerializer serializer];
        [manager POST:url parameters:parameter success:^(AFHTTPRequestOperation *operation, id responseObject)  {

            [[NSNotificationCenter defaultCenter] postNotificationName:@"registerToken" object:nil userInfo:nil];---breaking101

}
</code></pre>

<p>The notification code above is breaking. If I write 
<code>[[NSNotificationCenter defaultCenter] postNotificationName:@"registerToken" object:nil userInfo:nil];</code> at line1, it is working. I think it is related to some object issue. Please help. I have never used notification center.</p>