---
title: USDPreviewSession.Error.readOnlyStage
framework: spatialpreview
role: symbol
role_heading: Case
path: spatialpreview/usdpreviewsession/error/readonlystage
---

# USDPreviewSession.Error.readOnlyStage

The stage was replaced during optimization and any changes made to the stage won’t be synced.

## Declaration

```swift
case readOnlyStage
```