viewDidAppear not getting called

Another case where this will not be called at launch time (yet may be called on when you return to the view) will be is if you have subclassed UINavigationController and your subclass overrides

-(void)viewDidAppear:(BOOL)animated

but fails to call [super viewDidAppear:animated];

The only way I can reproduce the problem of child controllers not receiving appearance methods is if the container view controller does the following (which I'm sure you're not doing):

- (BOOL)automaticallyForwardAppearanceAndRotationMethodsToChildViewControllers
{
    return NO;
}

Perhaps you can try explicitly enabling this:

- (BOOL)automaticallyForwardAppearanceAndRotationMethodsToChildViewControllers
{
    return YES;
}

But my child view controllers definitely are getting the viewWillAppear calls (either if I explicitly automaticallyForwardAppearanceAndRotationMethodsToChildViewControllers or if I omit this altogether.

Update:

Ok, looking at the comments under your original question, it appears that the issue is that the child controller (B) in question is, itself, a container view controller (which is perfectly acceptable) presenting another child controller (C). And this controller B's own child controller C is being removed and you're wondering why you're not getting viewWillAppear or viewDidAppear for the container controller B. Container controllers do not get these appearance methods when their children are removed (or, more accurately, since containers should remove children, not children removing themselves, when the container removes a child, it does not receive the appearance methods).

If I've misunderstood the situation, let me know.

@Rob answer in Swift 4 (which helped me on my case which I was adding a childViewController to a UITabBarController)

override var shouldAutomaticallyForwardAppearanceMethods: Bool {
    return true
}

In my case, viewDidAppear was not called, because i have made unwanted mistake in viewWillAppear method.

-(void)viewWillAppear:(BOOL)animated {
    [super viewdidAppear:animated]; // this prevented my viewDidAppear method to be called
}