bevyengine/bevy · error · ReflectedRonDeserializeError::MissingReflectFromReflect

Attempted to load type

Error message

Attempted to load type "{0}", which does not have `ReflectFromReflect` in the type registry. This may occur for types that have opted-out of `FromReflect`

What it means

ReflectedRonDeserializeError::MissingReflectFromReflect is thrown by the RON asset loader when deserializing a value whose type has not had ReflectFromReflect (FromReflect) registered in the TypeRegistry. Bevy needs ReflectFromReflect to reconstruct the concrete value from reflected data. Types can lack it by omission or by explicitly opting out of FromReflect.

Solutions

Derive FromReflect (and Reflect) on the type and call app.register_type::<T>() so ReflectFromReflect is registered
If FromReflect is intentionally not derived, register the type data manually: app.register_type_data::<T, ReflectFromReflect>()
Check nested field types in the RON asset — the missing type may be deep in the struct, not the root
Register the types before triggering the asset load (e.g., in a plugin's build, not after)

Example fix

// before
#[derive(Reflect)]
struct LevelConfig { spawns: Vec<Spawn> }

// after
#[derive(Reflect, FromReflect)]
struct LevelConfig { spawns: Vec<Spawn> }
app.register_type::<LevelConfig>();
app.register_type::<Spawn>();

Defensive patterns

Strategy: validation

Validate before calling

fn is_registered_ron_ready<T: FromReflect + GetTypeRegistration>(app: &App) -> bool {
    let reg = app.world().resource::<AppTypeRegistry>().0.read();
    reg.get(TypeId::of::<T>()).map_or(false, |r| r.data::<ReflectFromReflect>().is_some())
}

Type guard

fn has_reflect_from_reflect(registry: &TypeRegistry, ty: TypeId) -> bool {
    registry.get(ty).map_or(false, |r| r.data::<ReflectFromReflect>().is_some())
}

Prevention

Register every type reachable from a RON asset, including nested fields
Derive FromReflect alongside Reflect
Run a startup check that all asset types are registered before loading

When it happens

Trigger: Loading a .ron asset whose registered type or any field's type was never derived/registered with ReflectDeserialize+FromReflect via #[reflect(...)] and app.register_type_data::<T, ReflectFromReflect>() (usually via #[derive(Reflect, FromReflect)] + register_type).

Common situations: Forgetting register_type::<T>() for a nested field type in a RON asset; a type that derives Reflect but opts out of FromReflect; plugin registration order leaving the type registry incomplete before asset load.

Related errors

AI-assisted analysis of bevyengine/bevy@a62cce8c05 (2026-09-19). Data as JSON: /api/errors/ab4112ed9447f76d. Report an issue: GitHub.

Appendix: source

Thrown at crates/bevy_asset/src/common_loaders/ron.rs:457

        Ok(writer.write_all(string.as_bytes()).await?)
    }
}

/// An error type for RON loading.
#[derive(Error, Debug)]
pub enum RonDeserializeError {
    #[error(transparent)]
    IoError(#[from] std::io::Error),
    #[error(transparent)]
    RonSpan(#[from] ron::de::SpannedError),
}

/// An error type for RON loading using reflection.
#[derive(Error, Debug)]
pub enum ReflectedRonDeserializeError {
    #[error(transparent)]
    Ron(#[from] RonDeserializeError),
    #[error("Attempted to load type \"{0}\", which does not have `ReflectFromReflect` in the type registry. This may occur for types that have opted-out of `FromReflect`")]
    MissingReflectFromReflect(&'static str),
    #[error("Attempted to load type \"{0}\", which does not have `ReflectAsset` in the type registry. Make sure to add `#[reflect(Asset)]` to your type")]
    MissingReflectAsset(&'static str),
}

/// An error type for RON saving.
#[derive(Error, Debug)]
pub enum RonSerializeError {
    #[error(transparent)]
    IoError(#[from] std::io::Error),
    #[error(transparent)]
    Ron(#[from] ron::Error),
}

/// An error type for RON saving using reflection.
#[derive(Error, Debug)]
pub enum ReflectedRonSerializeError {
    #[error(

View on GitHub (pinned to a62cce8c05)