Zabbix database upgrade error - Version mismatch - Cannot add or update a child row

[joicejames885]

Zabbix can't upgrade Database, any idea how to fix this?


17827:20160714:200414.156 current database version (mandatory/optional): 02030008/02030008
17827:20160714:200414.156 required mandatory version: 02040000
17827:20160714:200414.157 starting automatic database upgrade

[joicejames885]

Fixed it:

Removed constraint and after the upgrade added the constraint back.