---
title: "LanguageModelSession.GenerationError.decodingFailure(_:)"
framework: foundationmodels
role: symbol
role_heading: Case
path: "foundationmodels/languagemodelsession/generationerror/decodingfailure(_:)"
---

# LanguageModelSession.GenerationError.decodingFailure(_:)

An error that indicates the session failed to deserialize a valid generable type from model output.

## Declaration

```swift
case decodingFailure(LanguageModelSession.GenerationError.Context)
```

## Discussion

Discussion This can happen if generation was terminated early.

## See Also

### Generation errors

- [LanguageModelSession.GenerationError.assetsUnavailable(_:)](foundationmodels/languagemodelsession/generationerror/assetsunavailable(_:).md)
- [LanguageModelSession.GenerationError.exceededContextWindowSize(_:)](foundationmodels/languagemodelsession/generationerror/exceededcontextwindowsize(_:).md)
- [LanguageModelSession.GenerationError.guardrailViolation(_:)](foundationmodels/languagemodelsession/generationerror/guardrailviolation(_:).md)
- [LanguageModelSession.GenerationError.rateLimited(_:)](foundationmodels/languagemodelsession/generationerror/ratelimited(_:).md)
- [LanguageModelSession.GenerationError.refusal(_:_:)](foundationmodels/languagemodelsession/generationerror/refusal(_:_:).md)
- [LanguageModelSession.GenerationError.concurrentRequests(_:)](foundationmodels/languagemodelsession/generationerror/concurrentrequests(_:).md)
- [LanguageModelSession.GenerationError.unsupportedGuide(_:)](foundationmodels/languagemodelsession/generationerror/unsupportedguide(_:).md)
- [LanguageModelSession.GenerationError.unsupportedLanguageOrLocale(_:)](foundationmodels/languagemodelsession/generationerror/unsupportedlanguageorlocale(_:).md)
- [LanguageModelSession.GenerationError.Context](foundationmodels/languagemodelsession/generationerror/context.md)
- [LanguageModelSession.GenerationError.Refusal](foundationmodels/languagemodelsession/generationerror/refusal.md)