I  have an AD server with more than 500 groups, then groups are not listed in group directory tool. And I have got this error : 

javax.naming.OperationNotSupportedException: [LDAP: error code 12 - 00002040: SvcErr: DSID-0314043C, problem 5010 (UNAVAIL_EXTENSION), data 0 ]; remaining name 'OU=TOTO' at java.naming/com.sun.jndi.ldap.LdapCtx#mapErrorCode:3320 at java.naming/com.sun.jndi.ldap.LdapCtx#processReturnCode:3206 at java.naming/com.sun.jndi.ldap.LdapCtx#processReturnCode:2997 at java.naming/com.sun.jndi.ldap.LdapCtx#searchAux:1875 at java.naming/com.sun.jndi.ldap.LdapCtx#c_search:1798 at java.naming/com.sun.jndi.ldap.LdapCtx#c_search:1815 at java.naming/com.sun.jndi.toolkit.ctx.ComponentDirContext#p_search:418 at java.naming/com.sun.jndi.toolkit.ctx.PartialCompositeDirContext#search:396 at java.naming/com.sun.jndi.toolkit.ctx.PartialCompositeDirContext#search:378 at java.naming/javax.naming.directory.InitialDirContext#search:315 at org.ametys.core.util.ldap.AbstractLDAPConnector#_search:438 at org.ametys.core.util.ldap.AbstractLDAPConnector#_search:384 at org.ametys.plugins.core.impl.group.directory.ldap.LdapGroupDirectory#getGroups:708 at org.ametys.plugins.core.group.GroupSearchAction#_searchGroupsByContext:141