TestShib: unable to locate metadata for provider

[Sebastian Semrau]

Hello,

I try to test my shibboleth IDP with the TestShib SP. I uploaded the
metadata to TestShib and I enter the same entityID in the TestShib SP as
it is specified in the metadata of my IDP. I end up with the error
message below. What am I doing wrong or is it the service?

Error:
Identity provider lookup failed at
(https://sp.testshib.org/Shibboleth.sso/TestShib)

EntityID: https://idp.yn.de/idp/shibboleth

opensaml::saml2md::MetadataException: Unable to locate metadata for
identity provider (https://idp.yn.de/idp/shibboleth)

Thanks for your help,
Sebastian Semrau