Enter object with dsm
As you can see from your Krumo output (plus the very descriptive error message), data is an object, not an array. I'd imagine $display-&gt;context['panelizer'] is also an object but it's hard to say as you haven't mentioned in your question how that's populated. You should use either

$display-&gt;context['panelizer']['data']-&gt;field_centerpage_layout[0]['value']


or

$display-&gt;context['panelizer']-&gt;data-&gt;field_centerpage_layout[0]['value']


Probably the second one.