Hi, 

I'm trying to implement an amazon s3 Hive provider. I've basically followed the code of the built in IO provider but I am getting an error. I think I might have not configured it properly. 

Here is the error:

[ArgumentException: A parameter passed into a method was not a valid value
Parameter name: childRepositories]
   Umbraco.Framework.Mandate.That(Boolean condition, Func`2 defer) +28
   Umbraco.Framework.Mandate.ParameterCondition(Boolean condition, String paramName, String message) +110
   Umbraco.Framework.Mandate.ParameterNotNullOrEmpty(IEnumerable`1 sequence, String paramName) +94
   Umbraco.Hive.ProviderGrouping.EntityRepositoryGroup`1..ctor(IEnumerable`1 childRepositories, IEnumerable`1 childRevisionSessions, IEnumerable`1 childSchemaSessions, IEnumerable`1 childSchemaRevisionSessions, Uri idRoot, AbstractScopedCache scopedCache, IFrameworkContext frameworkContext, RepositoryContext hiveContext) +169
   Umbraco.Hive.ProviderGrouping.GroupUnit`1..ctor(IEnumerable`1 providerUnits, Uri idRoot, AbstractScopedCache scopedCache, Boolean canDisposeCache, IFrameworkContext frameworkContext, RepositoryContext hiveContext) +703
   Umbraco.Hive.ProviderGrouping.GroupUnitFactory.Create(AbstractScopedCache overrideCacheScope) +285
   Umbraco.Hive.ProviderGrouping.GroupUnitFactory`1.Create() +36
   Umbraco.Cms.Web.ContentExtensions.WriteUploadedFile(Guid mediaId, Boolean removeExistingFile, HttpPostedFileBase httpFile, IGroupUnitFactory`1 groupUnitFactory, HiveId existingFileId, String thumbSizes) +613

What am I missing?

Thanks,

Martin