Translating job items - Quota full - Internal Server Error

Thanks for the finding. The issue is caused by a missing exception handling in the batchRequestTranslation callback.

We need to improve the exception handling in the batchRequestTranslation callback.
The self::doRequest needs to be wrapped into a try/ catch block.

try {
      $result = self::doRequest($job, $query_params);
      // Collect translated texts with use of initial keys.
      foreach ($result['translations'] as $translated) {
        $translation[$keys_sequence[$i]]['#text'] = rawurldecode(Html::decodeEntities($translated['text']));
        $i++;
      }
      if (isset($context['results']) && isset($context['results']['translation']) && $context['results']['translation'] != NULL) {
        $context['results']['translation'] = array_merge($context['results']['translation'], $translation);
      }
      else {
        $context['results']['translation'] = $translation;
      }
      $context['results']['i'] = $i;
    } catch (TMGMTException $e) {
      \Drupal::messenger()->addError($e->getMessage());
    }

To overcome issues of incomplete translations in case of an error, the actual translation job needs to be resetted or deleted (needs to be evaluated) in the batchFinished callback.