             source = new (require "../sources/#{msg.type}") _.extend {}, msg.opts, sock:handle, logger:stream.log
             stream.addSource source
             @log.info "Added stream source: #{stream.key}/#{source.uuid}"
+            cb null
 
         rpc.on "group_source", (msg,handle,cb) =>
             sg = @stream_groups[ msg.group ]
             source = new (require "../sources/#{msg.type}") _.extend {}, msg.opts, sock:handle, logger:stream.log
             sg._stream.addSource source
             @log.info "Added group source: #{stream.key}/#{source.uuid}"
+            cb null
 
         af = _.after (Object.keys(@streams).length+Object.keys(@stream_groups).length), =>
             cb null

                            @log.error "Error loading rewind buffer: #{err}" if err
                            c.end()

                    rpc.request "stream_rewind", key:key,path:spath, (err) =>
                        return @log.error "Error loading rewind buffer for #{key}: #{err}" if err
                        @log.info "Rewind buffer loaded for #{key}"


            for source in sg._stream.sources
                if source._shouldHandoff
                    do (source) =>
                        @log.info "Sending StreamGroup source #{msg.key}/#{source.uuid}"
                        rpc.request "group_source",
                            group:      sg.key
                            type:       source.HANDOFF_TYPE
