With Tuleap 15.3.99.56 I am getting an error message then accessing https://tuleap-web.tuleap-aio-dev.docker/mediawiki_standalone/admin/migrations which is linked from the admin area in Tuleap.
The log shows
2023-12-15T09:48:20+00:00 [5470] [error] Caught exception: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'tuleap.plugin_mediawiki_database' doesn't exist:
#0 /usr/share/tuleap/src/vendor/paragonie/easydb/src/EasyDB.php(1458): PDO->prepare()
#1 /usr/share/tuleap/src/vendor/paragonie/easydb/src/EasyDB.php(1004): ParagonIE\EasyDB\EasyDB->prepare()
#2 /usr/share/tuleap/src/vendor/paragonie/easydb/src/EasyDB.php(948): ParagonIE\EasyDB\EasyDB->safeQuery()
#3 /usr/share/tuleap/plugins/mediawiki_standalone/include/Instance/Migration/Admin/LegacyReadyToMigrateDao.php(38): ParagonIE\EasyDB\EasyDB->run()
#4 /usr/share/tuleap/plugins/mediawiki_standalone/include/Instance/Migration/Admin/DisplayMigrationController.php(99): Tuleap\MediawikiStandalone\Instance\Migration\Admin\LegacyReadyToMigrateDao->searchProjectsUsingLegacyMediaWiki()
#5 /usr/share/tuleap/plugins/mediawiki_standalone/include/Instance/Migration/Admin/DisplayMigrationController.php(68): Tuleap\MediawikiStandalone\Instance\Migration\Admin\DisplayMigrationController->getProjects()
#6 /usr/share/tuleap/src/common/Request/FrontRouter.php(252): Tuleap\MediawikiStandalone\Instance\Migration\Admin\DisplayMigrationController->process()
#7 /usr/share/tuleap/src/common/Request/FrontRouter.php(110): Tuleap\Request\FrontRouter->routeHandler()
#8 /usr/share/tuleap/src/www/index.php(50): Tuleap\Request\FrontRouter->route()
#9 {main}
Apparently a database table is missing. Disabling/enabling as well as uninstalling/installing the plugin did not solve the issue.