751e44c4__Error_Codes___ServiceNow_Wiki__Description
[Error / Data Code] 1 [Error] LDAP_OPERATIONS_ERROR [Description] 
Indicates an internal error. The server is unable to respond with a more specific error and is also unable to properly respond to a request. It does not indicate that the client has sent an erroneous message. In NDS 8.3x through NDS 7.xx, this was the default error for NDS errors that did not map to an LDAP error code. To conform to the new LDAP drafts, NDS 8.5 uses 80 (0x50) for such errors.
LDAP Error Codes - ServiceNow Wiki
Description