Memory leak for NSOperationQueue observer?

Question

My app is randomly crashing as I have used KVO for NSOperationQueue. I did run instrument and found below ARC retain count situation.

and this is my code.

@try
{
    [[ApplicationManager sharedInstance].operationsQueue removeObserver:self forKeyPath:@"operations"];
}
@catch( NSException *exception )
{
    //NSLog(@"caught exception trying to remove an observer we are not observing");
}

[[ApplicationManager sharedInstance].operationsQueue addObserver:self forKeyPath:@"operations" options:0 context:NULL];

It would be great if you someone can point me right direction.