Shibboleth installation fails with IIS support checked

[Rod Widdowson]

> Any idea why having these Shibboleth modules installed is breaking my IIS, or how to troubleshoot?

I'm coming up blank.  I would check the native log which depending on config is a file or in the EV).  I'd also eyeball the IIS
configuration file (so much easier than the GUI) in particular I'd check that the isapi plugin isn't loaded.