ConstraintViolationException during import

Question

The import of a site failed with the following exception:

javax.jcr.nodetype.ConstraintViolationException: /sites/portail/accueil/header-top-right/button-link/style: 'btn-outline-inversed' 
    does not satisfy the constraint 'btn-red btn-big'

Cause

The version of the modules in both environments are not identical.

Solution

The version of modules has been synchronized in both environments.

A new export has been done and the import has succeeded in the destination environment.