Error: Data structure returned is not convertible in the requested format: Only integer keys supported for array columns on base level. Unsupported string 'steps' found for row 'array (
  0 =&gt; 
  array (
    'position' =&gt; 1,
    'name' =&gt; 'Homepage',
    'pattern_type' =&gt; 'path_equals',
    'pattern' =&gt; '/',
    'required' =&gt; false,
    'patternComparison' =&gt; 'path',
  ),
  1 =&gt; 
  array (
    'position' =&gt; 2,
    'name' =&gt; '50% off scuba diving masks promotion',
    'pattern_type' =&gt; 'path_equals',
    'pattern' =&gt; '/promotion/50-off-scuba-diving-masks',
    'required' =&gt; true,
    'patternComparison' =&gt; 'path',
  ),
  2 =&gt; 
  array (
    'position' =&gt; 3,
    'name' =&gt;'. Try to call this method with the parameters '&amp;format=original&amp;serialize=1'; you will get the original php data structure serialized.