{"record":{"id":"1e5f49d1f5dc545f","repo":"bevyengine/bevy","slug":"could-not-parse-ron-0","errorCode":null,"errorMessage":"Could not parse RON: {0}","messagePattern":"Could not parse RON: (.+?)","errorType":"exception","errorClass":"WorldAssetLoaderError","httpStatus":null,"severity":"error","filePath":"crates/bevy_world_serialization/src/world_asset_loader.rs","lineNumber":45,"sourceCode":"impl FromWorld for WorldAssetLoader {\n    fn from_world(world: &mut World) -> Self {\n        let type_registry = world.resource::<AppTypeRegistry>();\n        WorldAssetLoader {\n            type_registry: type_registry.0.clone(),\n        }\n    }\n}\n\n/// Possible errors that can be produced by [`WorldAssetLoader`]\n#[cfg(feature = \"serialize\")]\n#[non_exhaustive]\n#[derive(Debug, Error)]\npub enum WorldAssetLoaderError {\n    /// An [IO Error](std::io::Error)\n    #[error(\"Error while trying to read the world file: {0}\")]\n    Io(#[from] std::io::Error),\n    /// A [RON Error](ron::error::SpannedError)\n    #[error(\"Could not parse RON: {0}\")]\n    RonSpannedError(#[from] ron::error::SpannedError),\n}\n\n#[cfg(feature = \"serialize\")]\nimpl AssetLoader for WorldAssetLoader {\n    type Asset = DynamicWorld;\n    type Settings = ();\n    type Error = WorldAssetLoaderError;\n\n    async fn load(\n        &self,\n        reader: &mut dyn Reader,\n        _settings: &(),\n        load_context: &mut LoadContext<'_>,\n    ) -> Result<Self::Asset, Self::Error> {\n        let mut bytes = Vec::new();\n        reader.read_to_end(&mut bytes).await?;\n        let mut deserializer = ron::de::Deserializer::from_bytes(&bytes)?;","sourceCodeStart":27,"sourceCodeEnd":63,"githubUrl":"https://github.com/bevyengine/bevy/blob/396ca727080776bd313bb892423b7d94e03b81b4/crates/bevy_world_serialization/src/world_asset_loader.rs#L27-L63","documentation":"After the bytes are read, WorldAssetLoader parses the .world asset as RON (Rusty Object Notation). Any parse failure becomes WorldAssetLoaderError::RonSpannedError with \"Could not parse RON: {0}\", where ron::error::SpannedError embeds the exact line/column span of the syntax problem. Structurally valid but semantically wrong data (e.g. missing struct fields) can also surface here as RON/serde deserialization errors.","triggerScenarios":"Hand-editing a .world file and breaking syntax (unbalanced parentheses, missing commas, bad escapes); a world exported by a different Bevy/version or with different component types than the loading app expects; line-ending or encoding corruption; feeding JSON or another format to the RON parser.","commonSituations":"Level designers hand-tweaking serialized worlds; version drift between exporter and importer; merge conflicts in checked-in .world files; tooling that writes JSON into .world files.","solutions":["Read the span in the error message — RON reports the exact line and column to fix.","Round-trip a minimal world through your exporter to confirm the current format, and diff it against the failing file.","Re-export the world with the same Bevy/version and feature set as the loading app.","Validate edited files with a RON parser (ron::from_str on the string, or an editor RON plugin) before shipping.","Resolve merge conflicts in .world files by re-exporting rather than hand-merging."],"exampleFix":"# before: assets/worlds/level1.world (missing closing paren — span error points here)\n(\n    entities: {},\n    resources: {}\n\n# after\n(\n    entities: {},\n    resources: {},\n)","handlingStrategy":"try-catch","validationCode":"// validate RON in tooling or tests before shipping the asset\nfn ron_parses(source: &str) -> bool {\n    ron::from_str::<ron::value::Value>(source).is_ok()\n}","typeGuard":null,"tryCatchPattern":"match asset_server.get_load_state(&world_handle) {\n    Some(LoadState::Failed(err)) => {\n        if let bevy_asset::AssetLoadError::AssetLoaderError(loader_err) = &*err {\n            if let Some(WorldAssetLoaderError::RonSpannedError(spanned)) =\n                loader_err.error.downcast_ref::<WorldAssetLoaderError>()\n            {\n                // spanned.code / span carry the exact line & column to fix\n                error!(\"bad RON at {:?}: {}\", spanned.span, spanned.code);\n            }\n        }\n    }\n    _ => {}\n}","preventionTips":["Run ron::from_str over .world files in CI so syntax errors never merge.","Re-export worlds after Bevy upgrades instead of hand-editing across versions.","Prefer re-export over hand-merging .world files after conflicts.","Use the error's line/column span instead of eyeballing the whole file."],"tags":["rust","bevy","assets","serialization","ron","parse-error","world"],"backgroundTag":"ron-parse-error","analyzedSha":"396ca727080776bd313bb892423b7d94e03b81b4","analyzedAt":"2026-08-20T16:12:39.808Z","contentChangedAt":"2026-08-20T16:12:39.808Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}