Help with ldap authentication with AD

Hallo, my ldap authentication do not work, here is the part of the application file:

port: 8080
authentication: ldap
admin-groups: admins


  • name: admin
    password: password
    groups: admins
  • name: user
    password: password
    groups: users
    url: ldap://,ou=Gruppen,ou=IDT,dc=cit,dc=global
    user-dn-pattern: uid={0}
    user-search-filter: (sAMAccountName={0})
    group-search-base: cn=user
    group-search-filter: (member={0})
    manager-dn: cn=ldap-shiny,dc=cit,dc=global
    manager-password: xxxxxxxxxxxxxxx

The log-file has the following information:

2023-02-28 20:59:12.621 INFO 2664870 — [ XNIO-1 task-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 9 ms
2023-02-28 21:00:36.925 DEBUG 2664870 — [ XNIO-1 task-5] o.s.s.l.a.LdapAuthenticationProvider : Processing authentication request for user:
2023-02-28 21:00:36.929 DEBUG 2664870 — [ XNIO-1 task-5] o.s.s.l.a.BindAuthenticator : Attempting to bind as,cn=IDT_Benutzer,ou=Gruppen,ou=IDT,dc=cit,dc=global
2023-02-28 21:00:36.975 ERROR 2664870 — [ XNIO-1 task-5] w.a.UsernamePasswordAuthenticationFilter : An internal error occurred while trying to authenticate the user. Uncategorized exception occured during LDAP processing; nested exception is javax.naming.NamingException: LDAP connection has been closed
at ~[spring-security-ldap-5.3.4.RELEASE.jar!/:5.3.4.RELEASE]
at ~[spring-security-ldap-5.3.4.RELEASE.jar!/:5.3.4.RELEASE]
at ~[spring-security-core-5.3.4.RELEASE.jar!/:5.3.4.RELEASE]

Can anyone give me some guidance on locating the fault?
Many thanks