TYPO3 Core

It's said in the subject and it has nothing to do with the news extension.

Example:

Site configuration (yaml):

routeEnhancers:
  NewsPlugin:
    type: Extbase
    extension: News
    plugin: Pi1
    routes:
      - routePath: '/news/{news_title}'
        _controller: 'News::detail'
        _arguments:
          news_title: news
    aspects:
      news_title:
        type: PersistedAliasMapper
        tableName: tx_news_domain_model_news
        routeFieldName: path_segment

Page tsconfig:

TCEMAIN{
    preview {
        tx_news_domain_model_news {
            useCacheHash = 1
            previewPageId = 123
            useDefaultLanguageRecord = 0
            fieldToParameterMap {
                uid = tx_news_pi1[news_preview]
            }
            additionalGetParameters {
                tx_news_pi1.controller = News
                tx_news_pi1.action = detail
            }
        }
    }
}

When I will access the preview, it gives the following error:
(1/1) Symfony\Component\Routing\Exception\InvalidParameterException
Parameter "tx_news_pi1__news" for route "tx_news_pi1_0" must match "[^/]++" ("" given) to generate a corresponding URL.

Because of having no tx_news_pi1[news] variable, the url cannot be generated. It seems to be required always.

I tried to set the variable like this "{news_title?}" in the yaml configuration, wich is not respected (https://symfony.com/doc/current/routing.html#optional-parameters).
Also I found an option "strict_requirements", which will generate the url, when I set it in the core of the vendor (defined in vendor/symfony/routing/Route.php, set in vendor/symfony/routing/Router.php).

In the core of Typo3 the routing has no option, which I can set ("strict_requirements" option or the variable "{news_title?}" in yaml).

To set the news parameter like this "TCEMAIN.preview.tx_news_domain_model_news.additionalGetParameters.tx_news_pi1.news = " will produce an error too.