I am trying to implement CAS 5.2 with SAML2. I have been able to get the server configured as Idp and setup the client. However, the initial login gets a Bad Request message in the browser.
If I go back to the service while still logged in, it appears to work - I end up signed in on the other service with the correct user. Once I log out and login again - I get the bad request message.
I've added the log detail for troubleshooting SAML2 - but nothing jumps out at me as an issue.