Database conversion error starting digikam 5.1 trying to convert 4.14 database (MySQL external)

[mhoppstaedter]

Hi,

I just wanted to use Digikam 5.1 with my external MySQL database from digikam version 4.14. While trying to convert the database from version 7 to 8 digikam 5.1 produces the following error:

digikam.dbengine: Loading SQL code from config file "/usr/share/digikam/database/dbconfig.xml"
digikam.dbengine: Checking XML version ID => expected:  3  found:  3
digikam.coredb: Core database: running schema update
digikam.coredb: Core database: have a structure version  7
digikam.coredb: Core database: makeUpdates  7  to  8
digikam.dbengine: Failure executing query:
 ""
Error messages: "QMYSQL: Die Abfrage konnte nicht ausgeführt werden" "Cannot add or update a child row: a foreign key constraint fails (`digikam`.`#sql-47e_f03`, CONSTRAINT `Images_Albums` FOREIGN KEY (`album`) REFERENCES `Albums` (`id`) ON DELETE CASCADE ON UPDATE CASCADE)" 1452 2
Bound values:  ()
digikam.dbengine: Error while executing DBAction [ "UpdateSchemaFromV7ToV8" ] Statement [ "ALTER TABLE Images\n                                        ADD CONSTRAINT Images_Albums FOREIGN KEY (album) REFERENCES Albums (id) ON DELETE CASCADE ON UPDATE CASCADE,\n                                        ADD UNIQUE (album, name(255)),\n                                        ENGINE InnoDB;" ]
digikam.coredb: Core database: schema update to V 8 failed!
digikam.coredb: Core database: cannot process schema initialization

Has anyone a clue what I can do to get the database converted?

Thanks

Marco