751e44c4__Error_Codes___ServiceNow_Wiki__Description
[Error / Data Code] 49 / 773 [Error] USER MUST RESET PASSWORD [Description] 
Indicates an Active Directory (AD) AcceptSecurityContext data error. The user's password must be changed before logging on the first time. Returns only when presented with valid user-name and password credential.
LDAP Error Codes - ServiceNow Wiki
Description