IntlDateFormatter::formatObject() should not be called statically

I was happy to see the intl date handler but after I uploaded a site to a development server I get this error:

Block error: "Non-static method Symfony\Component\Intl\DateFormatter\IntlDateFormatter::formatObject() should not be called statically" in block type: "calendar"

in my config:

return [
    'debug' => true,
    'languages' => true,
    'date'  => [
        'handler' => 'intl'


<?php foreach ($block->calendar()->toStructure() as $item): 
  $start = $item->datum_start()->toDate('d MMMM');
  $eind  = $item->datum_eind()->toDate('d MMMM');
  $datum = $start . ' t/m ' . $eind;
    <td class="date"><?= $datum ?></td>
    <td class="org"><a href="<?= $item->link() ?>"><?= $item->organisatie() ?></a></td>
<?php endforeach ?>

Works fine locally with mamp pro and php 8.0.8 and 7.4, dev server runs 7.4 any thoughts?

The error points to the Intl extension being missing on your server (the namespace where it’s looking for the class is completely wrong).

Ok, thanks, enabled and happy