Error after SSO PHP errors ldap_search() ldap_get_entries()

Hello, i have a Apache2 Ubuntu Webserver. AD Auth works fine. sso on apache works fine too. My REMOTE_USER works.
Now when i click on sso i get this PHP errors:

Whats wrong here? Can you please help me?

Warning: ldap_search(): Search: Operations error in /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php on line 2872

Warning: ldap_get_entries() expects parameter 2 to be resource, boolean given in /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php on line 2873

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-login.php on line 423

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-login.php on line 436

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-admin/includes/misc.php on line 1144

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 948

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 949

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 950

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 951

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 952

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 953

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 956

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 957

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 960

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 961

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 962

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 963

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 966

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 967

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 968

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 969

Warning: Cannot modify header information – headers already sent by (output started at /var/www/html/wp-content/plugins/next-active-directory-integration/vendor/adLDAP/adLDAP.php:2872) in /var/www/html/wp-includes/pluggable.php on line 972