I’m trying to use SPNEGO (Kerberos) authentication with Active Directory – with CAS server (github). Here is official instruction: https://apereo.github.io/cas/5.1.x/installation/SPNEGO-Authentication.html I used this template: https://github.com/apereo/cas-overlay-template So pom.xmlis taken from there. Unfortunately, I only receive this exception: Question: What does it means? Which configuration element could make this issue? Answer I found the solution. In short: I have bad cas.authn.spnego.jcifsServicePrincipal in