Format string contains an unescaped latin alphabet character `n`

I’m have this error “Format string contains an unescaped latin alphabet character n for every automation run from UI path assistance. Once the msg box displayed it can only closed using task manager both the close button and ok buttons not working. Even though the error dialogue box displayed automations are executed sometimes and also automation can be run using studio without any issues.

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What is your UiPath Assistant version?
What error message do you see in Event Viewer → Application when the error occurred?

UiPath Assistant 23.4.0.

Application runs but the error massage is showing.

Use the Start diagnostic tool from UiPath Assistant and provide the zip file.

Are you sure that in your automation you are not having new lines (for example \n) somewhere in the Name, Description, …?

Did you try to rename the project in Studio → Publish → rename again in the Orchestrator process?

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No Error shows for every automation run form assistance even a simple message box activity with “Hello”

We are normally renaming the project names when adding to the orchestrator

I will send you the diagnosis details to your inbox

I have exactly the same issue running automations through the UiPath Assistant 2023.4.2 and didn’t manage to find any problems with my annotations and action names.
Can anyone advise how to debug this as validation checker in Studio does not seem to detect anything wrong…?


If you have issues with annotations in Studio, check if you enabled them in Settings → Design → Create docked annotations.

Create docked annotations - Select the default way in which annotations are added to activities: docked inside the activity (if the option is selected) or floating next to the activity (if the option is not selected).


Thanks Marian. I do not have issues with annotations, but decided to check them for any characters which may cause the above issues. However, no luck so far…

Good afternoon, is there any answer to this issue, I have the same problem.

-I have already deleted all the annotations
-Verify the Net.Framework version: 4.8

Once I get this error message, if I change the orchestrator account, the message still persists.

I am waiting for your help

I also encountered this problem, which occurred without using annotations; Is it related to Winodws11

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No Error is still there. And I am using a windows server OS

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if i run the robot from a bat file, the error message does not appear, so it is a problem of the UiPath wizard?

Even so, I want to be able to use the robot from the wizard, I share the diagnosis, in case it is necessary to find a solution.

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I have a similar issue but mine says Format string contains an unescaped latin alphabet character 'J'

The Process runs properly though. This just pops up out of nowhere, even when just clicking on the Process. I need to click on OK multiple times just to get rid of it. And then it pops up back again on the next Process run.

From the Event Viewer logs we observed these errors:

Faulting application name: UiPath.OutOfProcessUi.ServerHost.exe, version:, time stamp: 0xc05b8b37
Faulting module name: KERNELBASE.dll, version: 10.0.17763.1518, time stamp: 0xc4258670
Exception code: 0xe0434352
Fault offset: 0x001225f2
Faulting process id: 0x1b18
Faulting application start time: 0x01d9af8e93b067c4
Faulting application path: D:\Users\CENTRUM\.nuget\packages\uipath.formactivitylibrary\2.0.3\bin\net461\UiPath.OutOfProcessUi.ServerHost.exe
Faulting module path: C:\Windows\System32\KERNELBASE.dll
Report Id: 03cd0e86-a8e6-4212-b771-f38cc4626b6e
Faulting package full name: 
Faulting package-relative application ID: 
Aplicación: UiPath.OutOfProcessUi.ServerHost.exe
Versión de Framework: v4.0.30319
Descripción: el proceso terminó debido a una excepción no controlada.
Información de la excepción: System.InvalidCastException
   en System.StubHelpers.StubHelpers.GetCOMIPFromRCW(System.Object, IntPtr, IntPtr ByRef, Boolean ByRef)
   en Microsoft.Web.WebView2.Core.Raw.ICoreWebView2Controller.get_CoreWebView2()
   en Microsoft.Web.WebView2.Core.CoreWebView2Controller.get_CoreWebView2()
   en Microsoft.Web.WebView2.Wpf.WebView2.Uninitialize(Boolean)
   en Microsoft.Web.WebView2.Wpf.WebView2.Dispose(Boolean)
   en System.Windows.Interop.HwndHost.Finalize()

Also, you are having a Studio/Robot/Assistant 23.6 version.
Try to Upgrade the UiPath.Form.Activities package to 23.4.4 version.

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The error message persists:

My project is developed on windows-legacy, so the form package does not exist up to that version.

I have decided to create a new project to verify this new version of the form package.

I have uninstalled UiPath and removed any existing (nuget) packages.

Create the new project (“targetFramework”: “Windows”), it is just a main file and a form.

  "name": "Test Form",
  "projectId": "e92b8160-8b0d-4390-a652-918f6615da0e",
  "description": "Test Form",
  "main": "Main.xaml",
  "dependencies": {
    "UiPath.Excel.Activities": "[2.21.0-preview]",
    "UiPath.Form.Activities": "[23.4.4]",
    "UiPath.Mail.Activities": "[1.20.2]",
    "UiPath.System.Activities": "[23.6.0-preview]",
    "UiPath.Testing.Activities": "[23.6.0-preview]",
    "UiPath.UIAutomation.Activities": "[23.6.1-preview]"
  "webServices": [],
  "entitiesStores": [],
  "schemaVersion": "4.0",
  "studioVersion": "",
  "projectVersion": "1.0.1",
  "runtimeOptions": {
    "autoDispose": false,
    "netFrameworkLazyLoading": false,
    "isPausable": true,
    "isAttended": false,
    "requiresUserInteraction": true,
    "supportsPersistence": false,
    "workflowSerialization": "DataContract",
    "excludedLoggedData": [
    "executionType": "Workflow",
    "readyForPiP": false,
    "startsInPiP": false,
    "mustRestoreAllDependencies": true,
    "pipType": "ChildSession"
  "designOptions": {
    "projectProfile": "Developement",
    "outputType": "Process",
    "libraryOptions": {
      "includeOriginalXaml": false,
      "privateWorkflows": []
    "processOptions": {
      "ignoredFiles": []
    "fileInfoCollection": [],
    "modernBehavior": true
  "expressionLanguage": "VisualBasic",
  "entryPoints": [
      "filePath": "Main.xaml",
      "uniqueId": "dd86ba98-d567-4cff-8099-0121be99406b",
      "input": [],
      "output": []
  "isTemplate": false,
  "templateProjectData": {},
  "publishData": {},
  "targetFramework": "Windows"

Publish in the orchestrator

But the error persists


Maybe it is important to know this data

Version of Net Framework


  1. Provide the logs from the UiPath Assistant tool.

  1. Provide the full project sample archived in a zip file to try to test it internally. Make sure that the error is reproducible in Assitant.

share the files (225.6 KB)

Test Form.7z (93.9 KB)

Cannot reproduce the error in Assistant 2023.4.3.

You can find the installer here

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I just tested version 23.4.4 and the error persists.

This must be because of the pc then, these are the features:

Something additional does not allow me to use diagnostic tool of the wizard.


Now I am upgrading Windows, because it is managed by an external party.

What other data is needed?

It is a priority for me to remove this error message

Are you having the .Net installed in your system locale?
Try to change/add the English language to your system and restart the PC.
Let us know if this helped.

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