Alpha2 Metadata Error on Start

[Marvin Addison]

I'm seeing an error that looks like it's coming out of
system/conf/services-system.xml on startup:

12:58:53.511 - ERROR
[net.shibboleth.utilities.java.support.service.AbstractReloadableService:171]
- Service 'shibboleth.MetadataResolverService': initial load failed {}
net.shibboleth.utilities.java.support.service.ServiceException:
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name 'ShibbolethMetadata': Cannot create inner bean
'(inner bean)#3dc3740a' of type
[org.opensaml.saml.metadata.resolver.impl.ChainingMetadataResolver]
while setting constructor argument; nested exception is
org.springframework.beans.factory.BeanCreationException: Error
creating bean with name '(inner bean)#3dc3740a': Cannot create inner
bean '(inner bean)#79e15262' of type
[org.opensaml.saml.metadata.resolver.impl.FilesystemMetadataResolver]
while setting bean property 'resolvers' with key [0]; nested exception
is org.springframework.beans.factory.BeanCreationException: Error
creating bean with name '(inner bean)#79e15262': Invocation of init
method failed; nested exception is
net.shibboleth.utilities.java.support.component.ComponentInitializationException:
Error refreshing metadata during init
...
Caused by: net.shibboleth.utilities.java.support.resolver.ResolverException: net
.shibboleth.utilities.java.support.logic.ConstraintViolationException: Component
 ID can not be null or empty
        at org.opensaml.saml.metadata.resolver.impl.AbstractReloadingMetadataRes
olver.refresh(AbstractReloadingMetadataResolver.java:305) ~[opensaml-saml-impl-3
.0.0-alpha2.jar:na]
        at org.opensaml.saml.metadata.resolver.impl.AbstractReloadingMetadataRes
olver.initMetadataResolver(AbstractReloadingMetadataResolver.java:270) ~[opensam
l-saml-impl-3.0.0-alpha2.jar:na]
        ... 97 common frames omitted
Caused by: net.shibboleth.utilities.java.support.logic.ConstraintViolationExcept
ion: Component ID can not be null or empty

I don't see that I have anything configured that would cause this
problem, and I'm struggling to follow the cookie trail to where
FilesystemMetadataResolver is instantiated. I'm trying to get our v2
attribute-resolver.xml and attribute-filter.xml working in v3, so
maybe there's something in there that needs adjustment. That said, I
don't see any other errors in the logs to indicate problems with
resolver or filter configs. Suggestions?

Thanks,
M