Object deletes on composite adapter don't work

System.Exception: Error occurred when attempting to save entity with distinguished name

CN=100500

Error:

Unable to cast object of type 'Unify.Product.IdentityBroker.OperationalAdapter' to type 'Unify.Product.IdentityBroker.IAdapter'.
at Unify.Product.IdentityBroker.CompositeAdapter.DeleteEntityExceptionHandler(Action`1 adapterDeleteAction, IEnumerable`1 entityIds)
at Unify.Product.IdentityBroker.CompositeAdapter.DeleteEntity(Guid entityId)
at Unify.Product.IdentityBroker.AdapterNotifierDecoratorBase`1.DeleteEntity(Guid entityId)
at Unify.Product.IdentityBroker.LDIFAdapterBase.ExportChanges(ExportedLDIFForAdapter exportedLdifForAdapter)
at SyncInvokeExportChanges(Object , Object[] , Object[] )
at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)
at Unify.Product.IdentityBroker.IdentityBrokerManagementAgentProxy.ExportEntry(ModificationType modificationType, String[] changedAttributes, CSEntry csentry)
at Unify.Product.IdentityBroker.IdentityBrokerManagementAgent.ExportEntry(ModificationType modificationType, String[] changedAttributes, CSEntry csentry)