Resource type mismatch. Expected

Error message

Resource type mismatch. Expected: {expected}. Found: {type_uuid}

What it means

The From<UntypedResource> impl for Resource<T> converts an untyped resource into a typed one, but panics if the resource's actual type UUID differs from the expected T::type_uuid. This is a hard type check: the library prefers failing fast over silently wrapping a resource of the wrong type.

Solutions

Check untyped.resource_state/type_uuid before conversion, or use try_cast / cast::<T>() which returns Option instead of panicking.
Request the resource with the correct concrete type via resource_manager.request::<Texture>(path).
Fix the path/extension so the resource loads as the intended type.

Example fix

// before
let texture: TextureResource = model_untyped.into(); // panics on mismatch
// after
if let Some(texture) = model_untyped.cast::<Texture>() {
    // use texture
}

Defensive patterns

Strategy: type-guard

Validate before calling

let ok = untyped.type_uuid() == Some(<Texture as Reflect>::type_info().type_uuid);

Type guard

fn is_same_type<T: Reflect>(untyped: &UntypedResource) -> bool {
    untyped.type_uuid() == Some(<T as Reflect>::type_info().type_uuid)
}

Prevention

Always use UntypedResource::cast::<T>() (returns Option) instead of From/into for conversions.
Request resources as concrete types via resource_manager.request::<T>() rather than untyped + cast.
Verify asset extensions map to the intended loader/type when setting up paths.

When it happens

Trigger: Calling .into()/Resource::<T>::from(untyped) where untyped holds e.g. a Model while T is Texture; passing a resource loaded from a file whose extension/format does not match T.

Common situations: requesting resources generically then casting without checking; data files renamed/misconfigured so the wrong loader produced the resource; API changes where the expected resource type changed.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

AI-assisted analysis of FyroxEngine/Fyrox@76c91aad8e (2026-09-10). Data as JSON: /api/errors/0e739799262e5d95. Report an issue: GitHub.

Appendix: source

Thrown at fyrox-resource/src/lib.rs:494

impl<T> From<Uuid> for Resource<T>
where
    T: TypedResourceData,
{
    fn from(uuid: Uuid) -> Self {
        UntypedResource::from(uuid).into()
    }
}

impl<T> From<UntypedResource> for Resource<T>
where
    T: TypedResourceData,
{
    #[inline]
    fn from(untyped: UntypedResource) -> Self {
        if let Some(type_uuid) = untyped.type_uuid() {
            let expected = <T as Reflect>::type_info().type_uuid;
            if type_uuid != expected {
                panic!("Resource type mismatch. Expected: {expected}. Found: {type_uuid}");
            }
        }
        Self {
            untyped,
            phantom: Default::default(),
        }
    }
}

#[allow(clippy::from_over_into)]
impl<T> Into<UntypedResource> for Resource<T>
where
    T: TypedResourceData,
{
    #[inline]
    fn into(self) -> UntypedResource {
        self.untyped
    }

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