The "rdf_mapping" entity type does not exist.

Problem/Motivation

When ultimate cron runs the warmer job it fails with this message:

Drupal\Component\Plugin\Exception\PluginNotFoundException: The "rdf_mapping" entity type does not exist. in Drupal\Core\Entity\EntityTypeManager->getDefinition() (line 139 of /var/www/web/core/lib/Drupal/Core/Entity/EntityTypeManager.php).

any idea?
What should I investigate?

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes