Shibboleth setup.. So close but can use some help..

[Cantor, Scott]

By the way, there are about 700,000 threads in the archive on the same
exact error. Chances are one of them might explain the issue better than
I'm apparently able to do and probably will have log snippets that will
demonstrate which URL we're talking about. It will certainly have
something like /Shibboleth.sso/SAML2/POST or something similar in it.

-- Scott