Impossible de rejoindre le royaume : Permissions insuffisantes pour rejoindre le domaine

J'obtiens l'erreur suivante lorsque j'essaie de joindre la machine linux à AD :

$ realm join proxmox.local --computer-ou="CN=TEST,CN=Computers,DC=proxmox" --verbose

* Resolving: _ldap._tcp.proxmox.local
 * Resolving: proxmox.local
 * Performing LDAP DSE lookup on: 192.168.1.131
 * Successfully discovered: proxmox.local
Password for Administrator: 
 * Required files: /usr/sbin/oddjobd, /usr/libexec/oddjob/mkhomedir, /usr/sbin/sssd, /usr/sbin/adcli
 * LANG=C /usr/sbin/adcli join --verbose --domain proxmox.local --domain-realm PROXMOX.LOCAL --domain-controller 192.168.1.131 --computer-ou CN=TEST,CN=Computers,DC=proxmox --login-type user --login-user Administrator --stdin-password
 * Using domain name: proxmox.local
 * Calculated computer account name from fqdn: TEST
 * Using domain realm: proxmox.local
 * Sending netlogon pings to domain controller: cldap://192.168.1.131
 * Received NetLogon info from: windows.proxmox.local
 * Wrote out krb5.conf snippet to /var/cache/realmd/adcli-krb5-BihhIw/krb5.d/adcli-krb5-conf-PZ0Ypc
 * Authenticated as user: Administrator@PROXMOX.LOCAL
 ! Couldn't authenticate to active directory: SASL(-1): generic failure: GSSAPI Error: Unspecified GSS failure.  Minor code may provide more information (Server not found in Kerberos database)
adcli: couldn't connect to proxmox.local domain: Couldn't authenticate to active directory: SASL(-1): generic failure: GSSAPI Error: Unspecified GSS failure.  Minor code may provide more information (Server not found in Kerberos database)
 ! Insufficient permissions to join the domain
realm: Couldn't join realm: Insufficient permissions to join the domain

Mon krb5.conf :

# Configuration snippets may be placed in this directory as well
includedir /etc/krb5.conf.d/

[logging]
 default = FILE:/var/log/krb5libs.log
 kdc = FILE:/var/log/krb5kdc.log
 admin_server = FILE:/var/log/kadmind.log

[libdefaults]
 dns_lookup_realm = false
 dns_lookup_kdc = false
 rdns = false
 pkinit_anchors = /etc/pki/tls/certs/ca-bundle.crt
 # default_realm = PROXMOX.LOCAL 
 forwardable = true 
 default_tgs_enctypes = rc4-hmac des3-hmac-sha1 arcfour-hmac des-hmac-sha1 des-cbc-md5 des-cbc-crc
 default_tkt_enctypes = rc4-hmac des3-hmac-sha1 arcfour-hmac des-hmac-sha1 des-cbc-md5 des-cbc-crc
 permitted_enctypes = rc4-hmac des3-hmac-sha1 arcfour-hmac des-hmac-sha1 des-cbc-md5 des-cbc-crc

[realms]
 PROXMOX.LOCAL = {
   kdc = proxmox.local
   admin_server = proxmox.local
  }

[domain_realm]
 .proxmox.local = PROXMOX.LOCAL
 proxmox.local = PROXMOX.LOCAL

Le message d'erreur n'a pas de sens parce que j'utilise le compte Administrateur et qu'il dispose de tous les privilèges. Y a-t-il un moyen de déboguer ce problème ?