Error: Data structure returned is not convertible in the requested format: Multidimensional column values not supported. Found unexpected array value for column 'category' in row '0': 'array (
  'id' => 'CustomReports_CustomReports',
  'name' => 'Custom Reports',
  'order' => 65,
  'icon' => 'icon-business',
)'. Try to call this method with the parameters '&format=original&serialize=1'; you will get the original php data structure serialized.