{"record":{"id":"87d7a0e172453e97","repo":"BabylonJS/Babylon.js","slug":"could-not-deserialize-the-following-block-definiti","errorCode":null,"errorMessage":"Could not deserialize the following block definitions: ${blockDefinitionsWhichCouldNotBeDeserialized.join(\", \")}","messagePattern":"Could not deserialize the following block definitions: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packages/dev/smartFilters/src/serialization/smartFilterDeserializer.ts","lineNumber":86,"sourceCode":"        const blockNameMap = new Map<string, BaseBlock>();\r\n\r\n        // Deserialize the SmartFilter level data\r\n        smartFilter.comments = serializedSmartFilter.comments;\r\n        smartFilter.editorData = serializedSmartFilter.editorData;\r\n\r\n        // Deserialize the blocks\r\n        const blockDeserializationWork: Promise<void>[] = [];\r\n        const blockDefinitionsWhichCouldNotBeDeserialized: string[] = [];\r\n        serializedSmartFilter.blocks.forEach((serializedBlock: ISerializedBlockV1) => {\r\n            blockDeserializationWork.push(\r\n                this._deserializeBlockV1Async(smartFilter, serializedBlock, engine, blockDefinitionsWhichCouldNotBeDeserialized, blockIdMap, blockNameMap)\r\n            );\r\n        });\r\n        await Promise.all(blockDeserializationWork);\r\n\r\n        // If any block definitions could not be deserialized, throw an error\r\n        if (blockDefinitionsWhichCouldNotBeDeserialized.length > 0) {\r\n            throw new Error(`Could not deserialize the following block definitions: ${blockDefinitionsWhichCouldNotBeDeserialized.join(\", \")}`);\r\n        }\r\n\r\n        // Deserialize the connections\r\n        serializedSmartFilter.connections.forEach((connection: ISerializedConnectionV1) => {\r\n            // Find the source block and its connection point's connectTo function\r\n            const sourceBlock = typeof connection.outputBlock === \"string\" ? blockNameMap.get(connection.outputBlock) : blockIdMap.get(connection.outputBlock);\r\n\r\n            if (!sourceBlock) {\r\n                throw new Error(`Source block ${connection.outputBlock} not found`);\r\n            }\r\n            const sourceConnectionPoint = sourceBlock.outputs.find((output) => output.name === connection.outputConnectionPoint);\r\n            if (!sourceConnectionPoint || typeof sourceConnectionPoint.connectTo !== \"function\") {\r\n                throw new Error(`Block ${connection.outputBlock} does not have an connection point named ${connection.outputConnectionPoint}`);\r\n            }\r\n            const sourceConnectToFunction = sourceConnectionPoint.connectTo.bind(sourceConnectionPoint);\r\n\r\n            // Find the target block and its connection point\r\n            const targetBlock = typeof connection.inputBlock === \"string\" ? blockNameMap.get(connection.inputBlock) : blockIdMap.get(connection.inputBlock);\r","sourceCodeStart":68,"sourceCodeEnd":104,"githubUrl":"https://github.com/BabylonJS/Babylon.js/blob/0592b347b8a4ee0236089ea86a749cacfdb266d8/packages/dev/smartFilters/src/serialization/smartFilterDeserializer.ts#L68-L104","documentation":"During v1 deserialization of a Smart Filter, each block definition is deserialized in parallel; block types that have no registered deserializer (or whose deserializer throws) are collected by name instead of failing immediately. If any failed, the whole deserialization is rejected listing the offending block types. It means the runtime does not know how to reconstruct one or more block types present in the serialized filter.","triggerScenarios":"Deserializing a .smartfilter JSON that references custom block types never registered via the block registry/registerCustomBlockDefinition, deserializing with a bundle that omits certain block packages, or version skew where the block type was renamed between versions.","commonSituations":"Sharing filter files that use third-party or custom blocks without shipping the registration code, loading filters created in the Smart Filter editor into a minimal runtime bundle, upgrading Babylon.js/smartFilters and block type names changing.","solutions":["Register the missing custom block definitions before deserializing (registerCustomBlockDefinition / importing the module that defines the block).","Ensure the deserializer is given a runtime/dependency container that includes all block packages used by the filter.","Check blockType names in the JSON against registered types for case/spelling drift after upgrades.","Re-export the filter from the editor so it only uses available block types, or strip/replace the unsupported blocks.","Log blockDefinitionsWhichCouldNotBeDeserialized content to identify exactly which registrations are missing."],"exampleFix":"// before\nconst filter = await SmartFilterDeserializer.DeserializeAsync(runtime, container, json); // unknown custom type\n// after\nimport \"./myCustomBlocks/registerAll\"; // registers MyCustomBlock types\nconst filter = await SmartFilterDeserializer.DeserializeAsync(runtime, container, json);","handlingStrategy":"validation","validationCode":"function findUnregisteredTypes(serialized, registeredTypes) {\n  return (serialized.blockDefinitions ?? [])\n    .map((b) => b.blockType)\n    .filter((t) => t && !registeredTypes.has(t));\n}\n// call before DeserializeAsync; if result non-empty, register those types first","typeGuard":"function allBlockTypesRegistered(serialized, registry) {\n  return (serialized.blockDefinitions ?? []).every((b) => !b.blockType || registry.has(b.blockType));\n}","tryCatchPattern":"try {\n  const filter = await SmartFilterDeserializer.DeserializeAsync(runtime, container, json);\n} catch (e) {\n  const m = e.message.match(/Could not deserialize the following block definitions: (.+)/);\n  if (m) {\n    const missing = m[1].split(\", \");\n    throw new Error(`Register these block types first: ${missing.join(\", \")}`);\n  }\n  throw e;\n}","preventionTips":["Import every custom block module before deserialization.","Ship the same block packages used to author the filter.","After upgrades, diff serialized blockType names against the registry.","Pre-scan filter JSON block types against your registry as a smoke test.","Avoid stripping 'unused' block modules from bundles used for deserialization."],"tags":["smart-filters","deserialization","block-registry","version-skew"],"backgroundTag":"unregistered-block-type","analyzedSha":"0592b347b8a4ee0236089ea86a749cacfdb266d8","analyzedAt":"2026-08-30T15:11:20.442Z","schemaVersion":2},"datasetVersion":"2026-08-30T18:17:15.746Z"}