Kirby 4 Error - Structured content in Block

1

I have just updated my live website to Kirby 4. ONe of the block areas is now showing the following error.

Block error: "Kirby\Content\Content::__construct(): Argument #1 ($data) must be of type array, string given, called in /home/user-website/webapps/website/kirby/src/Cms/StructureObject.php on line 38" in block type: "icon-text"

This is the block’s snippet:

  <?php $listitems = $block->listitem()->toStructure();
  foreach ($listitems as $item):
  if ($icon = $item->icon()->toFile()): ?>
  <div class="col-11 icon-text" style="background-image: url(<?= $icon->url() ?>);">
  <?php endif ?>
    <h4 class="yellow"><?= $item->title() ?></h4>
    <p><?= $item->text() ?></p>
  </div>
  <?php endforeach ?>

And the Blueprint

name: Icon Text
icon: grid
label: Icon + text listing
tabs:
  content:
    fields:
      listitem:
        label: List Items
        type: structure
        fields:
          icon:
            label: Image/Icon
            type: files
            multiple: false
          title:
            label: Text
            type: text
          text:
            label: Content
            type: writer


  styles: fields/settingsColumn

Any reason why I would be getting this message - It wasn’t there in Kirby 3