@DavisA

Hi, using a hook (in a .module file):

function your_module_ckeditor5_plugin_info_alter(array &$plugin_definitions) {
  if (isset($plugin_definitions['ckeditor5_table'])) {
    $tableDefinition = $plugin_definitions['ckeditor5_table']->toArray();
    $bgColors = [
      '#0a2a3d',
    ];
    $borderColors = ['#eff0f2'];
    $tableDefinition['ckeditor5']['config']['table']['tableProperties'] = [
      'backgroundColors' => $bgColors,
      'borderColors' => $borderColors,
    ];
    $tableDefinition['ckeditor5']['config']['table']['tableCellProperties'] = [
      'backgroundColors' => $bgColors,
      'borderColors' => $borderColors,
    ];

    $plugin_definitions['ckeditor5_table'] = new CKEditor5PluginDefinition($tableDefinition);
  }
}

Agreed. Same faulty info @ https://www.drupal.org/docs/core-modules-and-themes/deprecated-and-obsol... →

The #14 (#2) core patch seems to have fixed the error in /admin/config/regional/content-language
However, when trying to import a .po file at /admin/config/regional/translate/import I got a similar error:

"The specified file fr.po could not be uploaded.
The referenced entity (file_type: undefined) does not exist."

I can just confirm as well. The function is the most heavest currently on the site and takes 1/3 of total load time.