configure cookie banner and error ininstallation

[Former user]

i had a following error in installation step, even the cookie banner is shown in the website. But i don't find how configure it .

 Doctrine \ DBAL \ Exception \ ForeignKeyConstraintViolationException
An exception occurred while executing 'ALTER TABLE atDateTime ADD CONSTRAINT FK_DF75412AA2A82A5D FOREIGN KEY (avID) REFERENCES AttributeValues (avID) ON DELETE CASCADE': SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`fcologni_2019`.`#sql-336694_cc1003`, CONSTRAINT `FK_DF75412AA2A82A5D` FOREIGN KEY (`avID`) REFERENCES `AttributeValues` (`avID`) ON DELETE CASCADE)
Previous exceptions

    SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`fcologni_2019`.`#sql-336694_cc1003`, CONSTRAINT `FK_DF75412AA2A82A5D` FOREIGN KEY (`avID`) REFERENCES `AttributeValues` (`avID`) ON DELETE CASCADE) (23000)
    SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`fcologni_2019`.`#sql-336694_cc1003`, CONSTRAINT `FK_DF75412AA2A82A5D` FOREIGN KEY (`avID`) REFERENCES `AttributeValues` (`avID`) ON DELETE CASCADE) (23000)