> For the complete documentation index, see [llms.txt](https://docs.yarnspinner.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yarnspinner.dev/3.1/api/csharp/yarn.compiler/yarn.compiler.diagnostic/yarn.compiler.diagnostic..ctor-4.md).

# Diagnostic(string,IToken,string,DiagnosticSeverity)

Constructor in [Diagnostic](/3.1/api/csharp/yarn.compiler/yarn.compiler.diagnostic.md)

## Summary

Initializes a new instance of the [Diagnostic](/3.1/api/csharp/yarn.compiler/yarn.compiler.diagnostic.md) class.

```csharp
public Diagnostic(string fileName, IToken token, string message, DiagnosticSeverity severity = DiagnosticSeverity.Error)
```

## Parameters

| Name                                                                                                                                                          | Description                                                         |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------- |
| `string` fileName                                                                                                                                             | Gets or sets the path, URI or file-name that the issue occurred in. |
| `Antlr4.Runtime.IToken` token                                                                                                                                 | The token at which the error occurred.                              |
| `string` message                                                                                                                                              | Gets or sets the description of the issue.                          |
| [Yarn.Compiler.Diagnostic.DiagnosticSeverity](/3.1/api/csharp/yarn.compiler/yarn.compiler.diagnostic/yarn.compiler.diagnostic.diagnosticseverity.md) severity | Gets or sets the severity of the issue.                             |