Keycloak 20.0.5 version: keycloak import realms doesnt work

Keycloak version : 20.0.5
importing cms-realm.json
System.setProperty(“keycloak.import”, “/opt/dell/cms/resources/cms-realm.json”);
System.setProperty(“keycloak.migration.realmName”, “cms”);
System.setProperty(“keycloak.migration.file”, “/opt/dell/cms/resources/cms-realm.json”);

2025-02-10 18:54:51 [main] INFO org.keycloak.services:89 - KC-SERVICES0031: Import of realm ‘cms’ requested. Strategy: IGNORE_EXISTING

ExportImportManager(session).runImport();
but the import is giving error as follows.
2025-02-10 18:54:51 [main] ERROR com.dell.ci.auth.provider.server.api.processing.KeycloakOperation:205 - Error importing runImport realm. Details: null.

Kindly suggest the fix for the above error.