Warning: Trying to access array offset on value of type null in Drupal\mmw_vademecum\Plugin\Block\DisplayPersonByGroupBlock->formatData() (line 117 of modules/custom/mmw_vademecum/src/Plugin/Block/DisplayPersonByGroupBlock.php).
Warning: foreach() argument must be of type array|object, null given in Drupal\mmw_vademecum\Plugin\Block\DisplayPersonByGroupBlock->formatData() (line 117 of modules/custom/mmw_vademecum/src/Plugin/Block/DisplayPersonByGroupBlock.php).
