Error: Data structure returned is not convertible in the requested format: Multidimensional column values not supported. Found unexpected array value for column 'match_form_rules' in row '0': 'array (
  0 => 
  array (
    'attribute' => 'form_id',
    'pattern' => 'equals_exactly',
    'value' => 'goog-gt-votingForm',
  ),
)'. Try to call this method with the parameters '&format=original&serialize=1'; you will get the original php data structure serialized.