Can't insert i18n keys into newly created i18n_messages tabl

Hi All

I get after creating a new i18n_messages table the following error when trying to synchronize the first messages entered as i18n keys:

com.servoy.j2db.persistence.RepositoryException: The Repository is not filled with the necessary defaults, missing: message_id The Repository is not filled with the necessary defaults, missing: message_id

I checked that the pk is set for the table as well as it has a servoy sequence assigned.
What is missing here?

Best regards, Robert