Popovers cannot be presented from a view which does not have a window

Question

What does this error indicate:

\"Popovers cannot be presented from a view which does not have a window.\"

Answer 1

I got this problem.

I had a UITabBarController as the detail view, and I set the barButtonItem as the leftBarButtonItem on all three navigation controllers in the tab bar.

vcChart.navigationItem.leftBarButtonItem = barButtonItem;
vcAnalysis.navigationItem.leftBarButtonItem = barButtonItem;
vcTechnicals.navigationItem.leftBarButtonItem = barButtonItem;

Turns out only the last one added is valid, and the previous two would throw the exception when tapped on.

To fix it, I only set the leftBarButtonItem for the visible view controller, and just switched the barButtonItem to the visible view controller every time the user switched tabs.