bevyengine/bevy · error

Attempted to insert invalid key of type {}.

Error message

Attempted to insert invalid key of type {}.

What it means

Panic in the reflected Map insert_boxed for BTreeMap: the key could not be converted from its reflected form into K (take_from_reflect failed), i.e. it is not a valid K. Insert keys of the map's declared key type; the offending type path is in the message.

Source

Thrown at crates/bevy_reflect/src/impls/alloc/collections/btree/map.rs:68

            result.push((
                Box::new(k) as Box<dyn PartialReflect>,
                Box::new(v) as Box<dyn PartialReflect>,
            ));
        }
        result
    }

    fn retain(&mut self, f: &mut dyn FnMut(&dyn PartialReflect, &mut dyn PartialReflect) -> bool) {
        self.retain(move |k, v| f(k, v));
    }

    fn insert_boxed(
        &mut self,
        key: Box<dyn PartialReflect>,
        value: Box<dyn PartialReflect>,
    ) -> Option<Box<dyn PartialReflect>> {
        let key = K::take_from_reflect(key).unwrap_or_else(|key| {
            panic!(
                "Attempted to insert invalid key of type {}.",
                key.reflect_type_path()
            )
        });
        let value = V::take_from_reflect(value).unwrap_or_else(|value| {
            panic!(
                "Attempted to insert invalid value of type {}.",
                value.reflect_type_path()
            )
        });
        self.insert(key, value)
            .map(|old_value| Box::new(old_value) as Box<dyn PartialReflect>)
    }

    fn remove(&mut self, key: &dyn PartialReflect) -> Option<Box<dyn PartialReflect>> {
        let mut from_reflect = None;
        key.try_downcast_ref::<K>()
            .or_else(|| {

View on GitHub (pinned to 396ca72708)

Solutions

1. Insert a key of the map's key type K
2. Ensure K implements FromReflect

When it happens

Trigger: Thrown at crates/bevy_reflect/src/impls/alloc/collections/btree/map.rs:68 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/ea2756542bcfcb76. Report an issue: GitHub.