问题
When adding an STS reference, I input the my windows azure federation metadata URL and it gives me the error in the title. It works if I create a new namespace, but a lot of stuff is configured on the current namespace, so I can't delete it.
回答1:
So for anyone that would get this error, it's a simple fix.
You need a X.509 certificate configured as primary in your ACS namespace.
To do this you go under your acs configurations, in certificates and keys then you add a X.509 by uploading a .pfx file to the server and entering the password.
You might also need a symmetric key also set as primary depending on your configuration.
来源：https://stackoverflow.com/questions/6330586/add-sts-reference-gives-error-the-security-token-service-descriptor-does-not-c