Bug: Exceptions loose their type when workflow is parallel and isolated

Hi together

if you throw an exception (like ArgumentException) within a workflow, which has called ‘isolated’, in a parallel activity; those exceptions will always loose their specialization.

Please use the xaml to reproduce. Bug reports.zip (3,2 KB)

Studio version doesn’t matter.

  "name": "BlankProcess",
  "description": "Blank Process",
  "main": "Main.xaml",
  "dependencies": {
	"Microsoft.Activities.Extensions": "[]",
	"UiPath.System.Activities": "[20.4.0]",
	"UiPath.UIAutomation.Activities": "[20.4.1]"
  "webServices": [],
  "schemaVersion": "4.0",
  "studioVersion": "",
  "projectVersion": "1.0.0",
  "runtimeOptions": {
	"autoDispose": false,
	"isPausable": true,
	"requiresUserInteraction": true,
	"supportsPersistence": false,
	"excludedLoggedData": [
	"executionType": "Workflow"
  "designOptions": {
	"projectProfile": "Developement",
	"outputType": "Process",
	"libraryOptions": {
	  "includeOriginalXaml": false,
	  "privateWorkflows": []
	"fileInfoCollection": []
  "expressionLanguage": "VisualBasic"

Thanks for your report, we will investigate.

Hi @Enrico

An update. Our team had a look and it was established that Isolated mode has a technical limitation that makes this a known behaviour.

It was documented here:

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