When you try to add a mapping via the UI, the following error appears:
Drupal\Core\Config\Schema\SchemaIncompleteException: Entity type 'Drupal\smartip_language_detection\Entity\SmartIpLanguageMapping' is missing 'config_export' definition in its annotation in Drupal\Core\Config\Entity\ConfigEntityBase->toArray() (line 252 of core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php).
It is because Drupal 9 requires config_export annotation for config entities, see https://www.drupal.org/node/2481909 → .
Add the missing config_export annotation
Fixed
2.0
Code
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.
Issue #3228265: Drupal 9 missing 'config_export' definitions