751e44c4__Error_Codes___ServiceNow_Wiki__Description
[Error / Data Code] 8 [Error] LDAP_STRONG_AUTH_REQUIRED [Description] 
Indicates one of the following: In bind requests, the LDAP server accepts only strong authentication. In a client request, the client requested an operation such as delete that requires strong authentication. In an unsolicited notice of disconnection, the LDAP server discovers the security protecting the communication between the client and server has unexpectedly failed or been compromised.
LDAP Error Codes - ServiceNow Wiki
Description