Maintenance Tab Error 500

[gaelle]

Hi,

Since I updated from 1.6 to 1.7 I cannot access the maintenance tab in admin panel.

I've got the following error :

UnexpectedTypeException 
in vendor/symfony/symfony/src/Symfony/Component/Form/Extension/Core/DataMapper/PropertyPathMapper.php (line 41)
public function mapDataToForms($data, $forms)    
{        
  $empty = null === $data || array() === $data;        
  if (!$empty && !is_array($data) && !is_object($data)) {            
    throw new UnexpectedTypeException($data, 'object, array or empty');        
  }        
  foreach ($forms as $form) {            
    $propertyPath = $form->getPropertyPath();            
    $config = $form->getConfig();
    
PropertyPathMapper->mapDataToForms('We are currently updating our shop and will be back really soon.<br>Thanks for your patience.', object(RecursiveIteratorIterator))

in vendor/symfony/symfony/src/Symfony/Component/Form/Form.php (line 383)
  // even if the form is compound.        
  if (count($this->children) > 0) {            
    // Update child forms from the data            
    $iterator = new InheritDataAwareIterator($this->children);            
    $iterator = new \RecursiveIteratorIterator($iterator);            
    $this->config->getDataMapper()->mapDataToForms($viewData, $iterator);        
  }

The maintenance text is coming from PS_MAINTENANCE_TEXT in PS_CONFIGURATION table.

Thanks

[Tonero]

There is a easy solution - delete "PS_MAINTENANCE_TEXT" record.