Can't uninstall the module through admin UI

Checking the issue!

Hi @freelylw

For uninstall the module go to Configuration > Web services > Simplenews > Settings and hit "Prepare uninstall".

Hi @freelylw,

I followed the steps given by viren18febS (it is also stated in the module the same instructions) and I confirmed that I was able to uninstall the Simplenews module.

Please look at the screenshot I attached for your reference,

Thank you.

Same Problem here with node.simplenews_issue field

Following these steps does not work for me. After running that purge, I still get the same error when running drush pmu -y simplenews. For some reason, this isn't removing the simplenews_issue field, leaving the module still unable to be installed:

  /**
   * Removes Simplenews fields.
   */
  public static function removeFields() {
    $field_config_storage = \Drupal::entityTypeManager()->getStorage('field_config');
    $simplenews_fields_ids = $field_config_storage->getQuery()
      ->condition('field_type', 'simplenews_', 'STARTS_WITH')->execute();
    $simplenews_fields = $field_config_storage->loadMultiple($simplenews_fields_ids);

    $field_config_storage->delete($simplenews_fields);
  }

OK, I found a workaround for this. I ran the prepare uninstall process as described, but still couldn't uninstall, so I manually removed all references to simplenews from the config (deleted all config files specific to simplenews and then edited out references to it in the others). Then drush cim uninstalled it as expected. I would not expect anyone without significant Drupal development experience to even think of that let alone know how to do it safely, so there is obviously work to be done on the module itself. I think a proper hook_uninstall implementation or something is needed here.