How to reproduce :

Set a LDAP Group directory

Type an invalid filter, for example : &((objectclass=groupOfNames),(cn=etudiants))

Validate the LDAP group directory

Seen result : 

the ldap group disappears without message, and we lost the complete configuration.

Log message dispalys : org.apache.avalon.framework.configuration.ConfigurationException: The group directory of id 'ldap' declares a model with id 'org.ametys.plugins.core.group.directory.Ldap' but some parameters are not valid:

• 'runtime.groups.ldap.filter': La valeur de ce champ n'est pas valide
  This group directory will be ignored. @file:/home/cms/Ametys_CMS/ametys_cms_home/config/group-directories.xml:12:17

Expected result : error message display and keep the paramater window opened.