Shibboleth SP 3.2.2 on IIS

[Cantor, Scott]

>    No matter what, when I do https://mysite.mydomain.com/Shibboleth.sso/status, I get a 404 error message. 

You should get a 500, not a 404. It's /Status, not /status. You also can't trust anything IIS says or does, because it's broken and it lies. In the case of errors, deliberately, because it defaults to refusing to report the actual information that the module returns anyway.

But a true 404 means it's flat out not listening and the module's not active, there's not much else to be said. I'd probably check the <Site> mapping in the SP configuration for a mismatch, as it ignores requests to a site with no mapping in place.

-- Scott