Failed to bind to server. ldap error #49 Invalid credentials

Hello Techyv buddies!
I've been receiving issues with the authentication of my LDAP. I am finding a resolution on the web but I didn't find anything that will help. The error I am receiving is stated below:
Binding with DN for non-anonymous search (cn=public-ldap,ou=Garda1UserTS,ou=service accounts,dc=garda1,dc=tlc). Using password entered in the form. Binding with DN for non-anonymous search (cn=public-ldap,ou=Garda1UserTS,ou=service accounts,dc=garda1,dc=tlc). Using password entered in the form. Failed to bind to server. ldap error #49 Invalid credentials
Following is the configuration of my LDAP:
sid = garda1pdc
name = garda1pdc
status = 1
ldap_type = ad
address = 192.168.21.1
port = 389
tls = 0
bind_method = 1
basedn = Array ( )
binddn = cn=public-ldap,ou=Garda1UserTS,ou=service accounts,dc=garda1,dc=tlc user_dn_expression =
user_attr = sAMAccountName
mail_attr = mail
mail_template =
unique_persistent_attr = objectsid
allow_conflicting_drupal_accts = 0
ldap_to_drupal_user =
testing_drupal_username = public-ldap
group_object_category =
search_pagination = 0
search_page_size = 1000
Can someone please provide a solution for this?
I would appreciate it.
