# UnknownLiteralNameTokenException Class

> Is thrown when calling the method MailMerge.MergeJsonData with a JSON string containing an unknown character sequence at a position where one of the strings "true", "false" or "null" are expected.

- **Product:** TX Text Control .NET for Windows Forms
- **Section:** Reference
- **Kind:** Class
- **Introduced:** 24.0
- **Namespace:** `TXTextControl.DocumentServer.Json`
- **Package:** `TXTextControl.TextControl.WinForms.SDK` (assembly `TXDocumentServer.dll`, from the private NuGet feed or Text Control Offline Packages)
- **.NET Framework:** reference `TXDocumentServer.dll` from the setup
- **Inherits:** `System.Exception` › `TXTextControl.DocumentServer.Json.ParserException`
- **Path:** TX Text Control .NET for Windows Forms > Reference > TXTextControl.DocumentServer.Json > UnknownLiteralNameTokenException Class
- **493 words**
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-json/unknownliteralnametokenexception/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-json/unknownliteralnametokenexception/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-json/unknownliteralnametokenexception/llms-full.txt

---

### Description

Is thrown when calling the method [MailMerge.MergeJsonData](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver/mailmerge/mergejsondata-method/llms-full.txt) with a JSON string containing an unknown character sequence at a position where one of the strings "true", "false" or "null" are expected.

### Syntax

```csharp
public class UnknownLiteralNameTokenException : ParserException
```

```vbnet
Public Class UnknownLiteralNameTokenException
    Inherits ParserException
```

### Examples

The following example creates an Unknown Literal Name Token Exception instance and configures its help link setting for a document workflow.

```csharp
TXTextControl.DocumentServer.Json.UnknownLiteralNameTokenException unknownLiteralNameTokenException = new(10, "CustomerName");
unknownLiteralNameTokenException.HelpLink = "Quarterly report";
```

```vbnet
Dim unknownLiteralNameTokenException As New TXTextControl.DocumentServer.Json.UnknownLiteralNameTokenException(10, "CustomerName")
unknownLiteralNameTokenException.HelpLink = "Quarterly report"
```

---

## Nearby

- **Previous:** [UnexpectedTokenException Class](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-json/unexpectedtokenexception/llms-full.txt)
- **Next:** [UnknownParseErrorException Class](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol-documentserver-json/unknownparseerrorexception/llms-full.txt)