7 methods override SystemConfigFormBase::validateForm()

BookSettingsForm::validateForm in drupal/core/modules/book/lib/Drupal/book/BookSettingsForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().
LocaleSettingsForm::validateForm in drupal/core/modules/locale/lib/Drupal/locale/Form/LocaleSettingsForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().
NegotiationUrlForm::validateForm in drupal/core/modules/language/lib/Drupal/language/Form/NegotiationUrlForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().
SearchSettingsForm::validateForm in drupal/core/modules/search/lib/Drupal/search/Form/SearchSettingsForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().
SimpletestSettingsForm::validateForm in drupal/core/modules/simpletest/lib/Drupal/simpletest/Form/SimpletestSettingsForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().
SiteInformationForm::validateForm in drupal/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().
UpdateSettingsForm::validateForm in drupal/core/modules/update/lib/Drupal/update/UpdateSettingsForm.php: Implements \Drupal\Core\Form\FormInterface::validateForm().