# OpcSessionActivationFailedEventHandler Delegate

> Reference: Represents the method that handles the SessionActivationFailed event.

<span class="api-meta">since v2.58</span>

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx.server">Opc.UaFx.Server</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
</dl>

Represents the method that handles the [SessionActivationFailed](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserver/members#sessionactivationfailed) event.

## Syntax

<div class="api-signature" data-lang="csharp">

```csharp
public delegate void OpcSessionActivationFailedEventHandler(
    object sender,
    OpcSessionActivationFailedEventArgs e)
```

</div>

<div class="api-signature" data-lang="vbnet">

```vbnet
Public Delegate Sub OpcSessionActivationFailedEventHandler(
    sender As Object,
    e As OpcSessionActivationFailedEventArgs)
```

</div>

## Parameters

| Name | Type | Description |
|---|---|---|
| `sender` | [Object](https://learn.microsoft.com/dotnet/api/system.object) | The server that rejected the activation. |
| `e` | [OpcSessionActivationFailedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcsessionactivationfailedeventargs/) | The data describing the rejected activation. |

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.58–v2.59 |