<!--
{
  "availability" : [
    "iOS: 17.0.0 -",
    "iPadOS: 17.0.0 -",
    "macCatalyst: 17.0.0 -",
    "macOS: 14.0.0 -",
    "tvOS: 17.0.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 10.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "DeveloperToolsSupport",
  "identifier" : "/documentation/DeveloperToolsSupport/PreviewUnavailable",
  "metadataVersion" : "0.1.0",
  "role" : "Structure",
  "symbol" : {
    "kind" : "Structure",
    "modules" : [
      "DeveloperToolsSupport"
    ],
    "preciseIdentifier" : "s:21DeveloperToolsSupport18PreviewUnavailableV"
  },
  "title" : "PreviewUnavailable"
}
-->

# PreviewUnavailable

An error that the system throws when a preview is unavailable at runtime.

```
struct PreviewUnavailable
```

## Overview

This type supports the expansion of preview macros. You don’t use it
directly.

## Topics

### Creating an instance

[`init()`](/documentation/DeveloperToolsSupport/PreviewUnavailable/init())

## Relationships

### Conforms To

[`Error`](/documentation/Swift/Error)

[`Sendable`](/documentation/Swift/Sendable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)