---
title: kAUGraphErr_OutputNodeErr
framework: audiotoolbox
role: symbol
role_heading: Global Variable
path: audiotoolbox/kaugrapherr_outputnodeerr
---

# kAUGraphErr_OutputNodeErr

Audio processing graphs can only contain one output unit. This error is returned if trying to add a second output unit or if the graph’s output unit is removed while the graph is running.

## Declaration

```swift
var kAUGraphErr_OutputNodeErr: OSStatus { get }
```

## See Also

### Constants

- [kAUGraphErr_CannotDoInCurrentContext](audiotoolbox/kaugrapherr_cannotdoincurrentcontext.md)
- [kAUGraphErr_InvalidAudioUnit](audiotoolbox/kaugrapherr_invalidaudiounit.md)
- [kAUGraphErr_InvalidConnection](audiotoolbox/kaugrapherr_invalidconnection.md)
- [kAUGraphErr_NodeNotFound](audiotoolbox/kaugrapherr_nodenotfound.md)