Try to remove fromView from superview:
[UIView animateWithDuration:[self transitionDuration:transitionContext]
animations:^{
if (self.isLoggedIn) {
//Perform animation
} else {
//Perform animation
}
} completion:^(BOOL finished) {
[fromViewController.view removeFromSuperview];
[transitionContext completeTransition:YES];
}];
}