Problem when trying to run proces from Robot machine

Hi.
When I’m trying to run process from robot machine, I’m getting the error below:

RemoteException wrapping System.Xaml.XamlObjectWriterException: Cannot create unknown type ‘{http://schemas.uipath.com/workflow/activities}SendExchangeMail’.
at System.Xaml.XamlObjectWriter.WriteStartObject(XamlType xamlType)
at System.Xaml.XamlWriter.WriteNode(XamlReader reader)
at System.Xaml.XamlServices.Transform(XamlReader xamlReader, XamlWriter xamlWriter, Boolean closeWriter)
at System.Activities.XamlIntegration.FuncFactory1.Evaluate() at System.Activities.DynamicActivity.OnInternalCacheMetadata(Boolean createEmptyBindings) at System.Activities.Activity.InternalCacheMetadata(Boolean createEmptyBindings, IList1& validationErrors)
at System.Activities.ActivityUtilities.ProcessActivity(ChildActivity childActivity, ChildActivity& nextActivity, Stack1& activitiesRemaining, ActivityCallStack parentChain, IList1& validationErrors, ProcessActivityTreeOptions options, ProcessActivityCallback callback)
at System.Activities.ActivityUtilities.ProcessActivityTreeCore(ChildActivity currentActivity, ActivityCallStack parentChain, ProcessActivityTreeOptions options, ProcessActivityCallback callback, IList1& validationErrors) at System.Activities.ActivityUtilities.CacheRootMetadata(Activity activity, LocationReferenceEnvironment hostEnvironment, ProcessActivityTreeOptions options, ProcessActivityCallback callback, IList1& validationErrors)
at System.Activities.Hosting.WorkflowInstance.ValidateWorkflow(WorkflowInstanceExtensionManager extensionManager)
at System.Activities.Hosting.WorkflowInstance.RegisterExtensionManager(WorkflowInstanceExtensionManager extensionManager)
at System.Activities.WorkflowApplication.EnsureInitialized()
at System.Activities.WorkflowApplication.Enqueue(InstanceOperation operation, Boolean push)
at System.Activities.WorkflowApplication.SimpleOperationAsyncResult.Run(TimeSpan timeout)
at System.Activities.WorkflowApplication.BeginRun(AsyncCallback callback, Object state)
at UiPath.Executor.RobotRunner.d__93.MoveNext()

Can someone help me to solve the problem?

@okalinic

Looks like a package issue

To make sure the packages are downloaded properly…go to c:\users\username\.nuget folder and from there rename the system and mail packages and rerun so that the packages are downloaded again

Cheers