The staged import tools will fail, if you try to import a record that has a title longer than 128 characters, as import_biblios.title is varchar(128). In comparison, biblio.title is mediumtext. We should make the fields match up or at least extend the size of import_biblios.title.
I've tried to update locally to mediumtext, but this appears to fail because title is part of the PK.
This is an "old version" problem. In master, this table is 'prettier': DROP TABLE IF EXISTS `import_biblios`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `import_biblios` ( `import_record_id` int(11) NOT NULL, `matched_biblionumber` int(11) DEFAULT NULL, `control_number` varchar(25) COLLATE utf8mb4_unicode_ci DEFAULT NULL, `original_source` varchar(25) COLLATE utf8mb4_unicode_ci DEFAULT NULL, `title` longtext COLLATE utf8mb4_unicode_ci DEFAULT NULL, `author` longtext COLLATE utf8mb4_unicode_ci DEFAULT NULL, `isbn` longtext COLLATE utf8mb4_unicode_ci DEFAULT NULL, `issn` longtext COLLATE utf8mb4_unicode_ci DEFAULT NULL, `has_items` tinyint(1) NOT NULL DEFAULT 0, KEY `import_biblios_ibfk_1` (`import_record_id`), KEY `matched_biblionumber` (`matched_biblionumber`), KEY `title` (`title`(191)), KEY `isbn` (`isbn`(191)), CONSTRAINT `import_biblios_ibfk_1` FOREIGN KEY (`import_record_id`) REFERENCES `import_records` (`import_record_id`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci; /*!40101 SET character_set_client = @saved_cs_client */;