Migrator Blues - Undefined Offset: 1

Hey little trouble migrating this collection to v3. The collection is called organisations and is sorted numerically, it has a couple drafts within still..

this is an imgur link to a pic of the structure

Heres the error I’m getting, site is not a multisite:

   ErrorException 

  Undefined offset: 1

  at vendor/statamic/migrator/src/CollectionMigrator.php:222
    218▕ 
    219▕         // If filename has order key, store order and remove order key.
    220▕         if ($this->config->get('order') === 'number') {
    221▕             preg_match($regex = '/^([0-9]+)\./', $filename, $matches);
  ➜ 222▕             $this->entryOrder[$matches[1]] = $entry['id'];
    223▕             $filename = preg_replace($regex, '', $filename);
    224▕         }
    225▕ 
    226▕         // If multisite, ensure site subfolder.

      +20 vendor frames 
  21  please:37
      Illuminate\Foundation\Console\Kernel::handle(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))