bevyengine/bevy · error · AssetWriterError

encountered an io error while loading asset: {0}

Error message

encountered an io error while loading asset: {0}

What it means

AssetWriterError::Io: the asset writer encountered an underlying std::io::Error while writing asset bytes or metadata (disk full, permissions, interrupted write, etc.). The write to the asset destination failed at the OS level.

Source

Thrown at crates/bevy_asset/src/io/mod.rs:325

    fn read_meta_bytes<'a>(
        &'a self,
        path: &'a Path,
    ) -> BoxedFuture<'a, Result<Vec<u8>, AssetReaderError>> {
        Box::pin(Self::read_meta_bytes(self, path))
    }
}

/// A convenience type for an [`AsyncWrite`] object plus the traits it needs to satisfy.
pub type Writer = dyn AsyncWrite + Unpin + Send + Sync;

/// A convenience type for a stream of pathnames plus the traits it needs to satisfy.
pub type PathStream = dyn Stream<Item = PathBuf> + Unpin + Send;

/// Errors that occur while loading assets.
#[derive(Error, Debug)]
pub enum AssetWriterError {
    /// Encountered an I/O error while loading an asset.
    #[error("encountered an io error while loading asset: {0}")]
    Io(#[from] std::io::Error),
}

/// Performs write operations on an asset storage. [`AssetWriter`] exposes a "virtual filesystem"
/// API, where asset bytes and asset metadata bytes are both stored and accessible for a given
/// `path`. This trait is not object safe, if needed use a dyn [`ErasedAssetWriter`] instead.
///
/// This trait defines asset-agnostic mechanisms to write bytes to a storage system.
/// For the per-asset-type saving/loading logic, see [`AssetSaver`](crate::saver::AssetSaver) and [`AssetLoader`](crate::loader::AssetLoader).
///
/// For a complementary version of this trait that can read assets from storage, see [`AssetReader`].
pub trait AssetWriter: Send + Sync + 'static {
    /// Writes the full asset bytes at the provided path.
    fn write<'a>(
        &'a self,
        path: &'a Path,
    ) -> impl ConditionalSendFuture<Output = Result<Box<Writer>, AssetWriterError>>;
    /// Writes the full asset meta bytes at the provided path.

View on GitHub (pinned to 396ca72708)

Solutions

1. Inspect the wrapped io::Error for the concrete cause
2. Free disk space / fix permissions on the asset output directory
3. Retry the write: transient io failures during processing may succeed on reprocessing

When it happens

Trigger: Thrown at crates/bevy_asset/src/io/mod.rs:325 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/1854c37cae5fdc76. Report an issue: GitHub.