## ReconnectingWebSocket.onerror property [​](/content/docs/sdk/core.reconnectingwebsocket.onerror#reconnectingwebsocketonerror-property/index.html)

An event listener to be called when an error occurs

**Signature:**

```typescript
onerror: ((event: ErrorEvent) => void) | null;
```

- [ReconnectingWebSocket.onerror property](/content/docs/sdk/core.reconnectingwebsocket.onerror#reconnectingwebsocketonerror-property/index.html)