bevyengine/bevy · error · GetComponentReflectError::MissingReflectFromPtrTypeData

The `World`'s `TypeRegistry` did not contain `TypeData` for

Error message

The `World`'s `TypeRegistry` did not contain `TypeData` for `ReflectFromPtr` for the given {0:?} (did you call `App::register_type()`?)

What it means

GetComponentReflectError::MissingReflectFromPtrTypeData is returned by World::get_reflect / get_reflect_mut when the type IS present in the TypeRegistry but lacks the ReflectFromPtr type data needed to convert a raw component pointer into a &dyn Reflect. ReflectFromPtr is attached automatically by #[derive(Reflect)], so its absence means the type got into the registry through a partial/manual registration (or a non-Reflect proxy) rather than a full register_type call.

Source

Thrown at crates/bevy_ecs/src/world/reflect.rs:253

        component_name: Option<DebugName>,
    },

    /// The [`World`] was missing the [`AppTypeRegistry`] resource.
    #[error("The `World` was missing the `AppTypeRegistry` resource")]
    MissingAppTypeRegistry,

    /// The [`World`]'s [`TypeRegistry`] did not contain [`TypeData`] for [`ReflectFromPtr`] for the given [`TypeId`].
    ///
    /// This is usually handled by calling [`App::register_type`] for the type corresponding to
    /// the given [`TypeId`].
    ///
    /// See the documentation for [`bevy_reflect`] for more information.
    ///
    /// [`TypeData`]: bevy_reflect::TypeData
    /// [`TypeRegistry`]: bevy_reflect::TypeRegistry
    /// [`ReflectFromPtr`]: bevy_reflect::ReflectFromPtr
    /// [`App::register_type`]: ../../../bevy_app/struct.App.html#method.register_type
    #[error("The `World`'s `TypeRegistry` did not contain `TypeData` for `ReflectFromPtr` for the given {0:?} (did you call `App::register_type()`?)")]
    MissingReflectFromPtrTypeData(TypeId),
}

#[cfg(test)]
mod tests {
    use core::any::TypeId;

    use bevy_reflect::Reflect;

    use crate::prelude::{AppTypeRegistry, Component, DetectChanges, World};

    #[derive(Component, Reflect)]
    struct RFoo(i32);

    #[derive(Component)]
    struct Bar;

    #[test]

View on GitHub (pinned to 396ca72708)

Solutions

Derive Reflect on the component (#[derive(Component, Reflect)]) and register with app.register_type::<T>() so ReflectFromPtr is generated.
If you cannot derive, implement/attach the data explicitly: registry.get_mut(type_id).unwrap().insert(<ReflectFromPtr as FromReflect>::from_reflect(...)) or use bevy_reflect's registration helpers.
Pre-check before access: app_type_registry.read().get_type_data::<ReflectFromPtr>(TypeId::of::<T>()).is_some() and skip with a clear log.
After upgrading Bevy or swapping reflect crates, wipe stale registry state and re-register all reflected types.

Example fix

// before
#[derive(Component)] struct Health(f32); // no Reflect derive
registry.write().register::<Health>(); // partial registration
let c = world.get_reflect(e, TypeId::of::<Health>())?; // MissingReflectFromPtrTypeData

// after
#[derive(Component, Reflect)] struct Health(f32);
app.register_type::<Health>();
let c = world.get_reflect(e, TypeId::of::<Health>())?;

Defensive patterns

Strategy: validation

Validate before calling

let registry = world.resource::<AppTypeRegistry>().0.clone();
let has_from_ptr = registry
    .read()
    .get_type_data::<ReflectFromPtr>(TypeId::of::<T>())
    .is_some();
if !has_from_ptr {
    registry.write().register::<T>(); // full registration attaches ReflectFromPtr
}

Try / catch

match world.get_reflect(entity, TypeId::of::<T>()) {
    Err(GetComponentReflectError::MissingReflectFromPtrTypeData(id)) => {
        debug!("type {id:?} registered without ReflectFromPtr; re-register with #[derive(Reflect)]");
    }
    other => { /* ... */ }
}

Prevention

Derive Reflect rather than hand-rolled partial registration for reflected components.
After Bevy upgrades, re-register all reflected types to refresh TypeData.
Probe get_type_data::<ReflectFromPtr> before low-level reflective pointer work.

When it happens

Trigger: world.get_reflect(entity, TypeId::of::<T>()) where T was registered manually via registry.register_type_data or wrapped without deriving Reflect; types registered only as primitives/opaque; a version mix where an old serialized TypeId maps to a type registered differently; reflecting a type registered through ReflectDefault-only paths.

Common situations: Custom registration code that adds TypeData piecemeal instead of deriving Reflect and calling app.register_type; hot-reload/editor pipelines registering placeholder types; third-party components with hand-written Reflect impls missing FromReflect/ReflectFromPtr.

Related errors

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/d55653f8929f6eb9. Report an issue: GitHub.