Custom package access through Orchestrator


I created a custom activity called “AmazonS3Service” and added it to UiPath studio
Its working fine in Studio, but when i deploy it in orchestrator i am getting the exception

• Info : “Execution error : System.Xaml.XamlObjectWriterException: Cannot create unknown type ‘{clr-namespace:AmazonS3Service;assembly=AmazonS3Service}UploadDirectory’.\r\n at System.Xaml.XamlObjectWriter.WriteStartObject(XamlType xamlType)\r\n at System.Xaml.XamlWriter.WriteNode(XamlReader reader)\r\n at System.Xaml.XamlServices.Transform(XamlReader xamlReader, XamlWriter xamlWriter, Boolean closeWriter)\r\n at System.Activities.XamlIntegration.FuncFactory1.Evaluate()\r\n at System.Activities.DynamicActivity.OnInternalCacheMetadata(Boolean createEmptyBindings)\r\n at System.Activities.Activity.InternalCacheMetadata(Boolean createEmptyBindings, IList1& validationErrors)\r\n at System.Activities.ActivityUtilities.ProcessActivity(ChildActivity childActivity, ChildActivity& nextActivity, Stack1& activitiesRemaining, ActivityCallStack parentChain, IList1& validationErrors, ProcessActivityTreeOptions options, ProcessActivityCallback callback)\r\n at System.Activities.ActivityUtilities.ProcessActivityTreeCore(ChildActivity currentActivity, ActivityCallStack parentChain, ProcessActivityTreeOptions options, ProcessActivityCallback callback, IList1& validationErrors)\r\n at System.Activities.ActivityUtilities.CacheRootMetadata(Activity activity, LocationReferenceEnvironment hostEnvironment, ProcessActivityTreeOptions options, ProcessActivityCallback callback, IList1& validationErrors)\r\n at System.Activities.Hosting.WorkflowInstance.ValidateWorkflow(WorkflowInstanceExtensionManager extensionManager)\r\n at System.Activities.Hosting.WorkflowInstance.RegisterExtensionManager(WorkflowInstanceExtensionManager extensionManager)\r\n at System.Activities.WorkflowApplication.EnsureInitialized()\r\n at System.Activities.WorkflowApplication.Enqueue(InstanceOperation operation, Boolean push)\r\n at System.Activities.WorkflowApplication.SimpleOperationAsyncResult.Run(TimeSpan timeout)\r\n at System.Activities.WorkflowApplication.BeginRun(AsyncCallback callback, Object state)\r\n at UiPath.Executor.RobotRunner.<>c__DisplayClass52_0.b__0()”


are you getting this error when you are running the job from Orchestrator on some other machine?
If yes then you have to place the custom activity nuget package in Orchestrator activity feed so that other bots can download it from here before running the job.

If you have Orchestrator older than 2016.2 then you have to install it manually on robot machines or place it in some shared location from which robot can actually access and install it


Hi Jishnu,

I have the same issue, how to upload the custom package in Orchestrator activity?
BTW, the other robot has installed the same custom package but NOT work.



Hi fankieyu,

You have to manually place the activities in the Activities folder available in Orchestrator installation directory.

The idea is that the robot should be able to resolve the dependencies. A robot looks for the packages in :-
c)Orchestrator feed

If the required package is available in any of the source it will download and install automatically.