{"record":{"id":"8b8335cfd49c8d4d","repo":"BabylonJS/Babylon.js","slug":"cannot-load-file-a-valid-scene-filename-or-root-u","errorCode":null,"errorMessage":"Cannot load file: a valid scene filename or root url was not provided.","messagePattern":"Cannot load file: a valid scene filename or root url was not provided\\.","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packages/dev/core/src/Loading/sceneLoader.ts","lineNumber":985,"sourceCode":"}\r\n\r\nasync function importMeshCoreAsync(\r\n    meshNames: string | readonly string[] | null | undefined,\r\n    rootUrl: string,\r\n    sceneFilename: SceneSource = \"\",\r\n    scene: Nullable<Scene> = EngineStore.LastCreatedScene,\r\n    onProgress?: Nullable<(event: ISceneLoaderProgressEvent) => void>,\r\n    pluginExtension?: Nullable<string>,\r\n    name = \"\",\r\n    pluginOptions: PluginOptions = {}\r\n): Promise<ISceneLoaderAsyncResult> {\r\n    if (!scene) {\r\n        throw new Error(\"No scene available to import mesh to\");\r\n    }\r\n\r\n    const fileInfo = GetFileInfo(rootUrl, sceneFilename);\r\n    if (!fileInfo) {\r\n        throw new Error(\"Cannot load file: a valid scene filename or root url was not provided.\");\r\n    }\r\n\r\n    const loadingToken = {};\r\n    scene.addPendingData(loadingToken);\r\n\r\n    const progressHandler = wrapProgress(onProgress);\r\n\r\n    try {\r\n        const { plugin, data, responseURL } = await loadDataAsync(fileInfo, scene, progressHandler, pluginExtension ?? null, name, pluginOptions);\r\n\r\n        if (plugin.rewriteRootURL) {\r\n            fileInfo.rootUrl = plugin.rewriteRootURL(fileInfo.rootUrl, responseURL);\r\n        }\r\n\r\n        let result: ISceneLoaderAsyncResult;\r\n        try {\r\n            result = await toAsyncPlugin(plugin, fileInfo).importMeshAsync(meshNames, scene, data, fileInfo.rootUrl, progressHandler, fileInfo.name);\r\n        } catch (error) {\r","sourceCodeStart":967,"sourceCodeEnd":1003,"githubUrl":"https://github.com/BabylonJS/Babylon.js/blob/0592b347b8a4ee0236089ea86a749cacfdb266d8/packages/dev/core/src/Loading/sceneLoader.ts#L967-L1003","documentation":"After the scene check, SceneLoader calls GetFileInfo(rootUrl, sceneFilename) to normalize the target into a URL/file descriptor. If both the rootUrl+sceneFilename combination resolve to nothing (empty strings, null filename with no rootUrl), the loader has nothing to fetch and throws this error.","triggerScenarios":"Calling ImportMeshAsync/AppendAsync with rootUrl = \"\" and sceneFilename = \"\"/null, or passing null for both arguments.","commonSituations":"Building the path from a config value that was empty; forgetting to concatenate the filename; refactoring to data-driven URLs where the key is missing; calling the API with defaults expecting a bundled default model.","solutions":["Pass a valid rootUrl and sceneFilename, e.g. \"assets/\" and \"scene.glb\".","Verify the variable holding the path/filename is non-empty before the call.","If loading from raw data, switch to the data-loading entry point with an explicit pluginExtension instead."],"exampleFix":"// before\nawait SceneLoader.ImportMeshAsync(\"\", \"\", \"\", scene); // throws\n\n// after\nawait SceneLoader.ImportMeshAsync(\"\", \"assets/models/\", \"scene.glb\", scene);","handlingStrategy":"validation","validationCode":"if (!rootUrl && !sceneFilename) {\n  throw new Error(\"Provide at least a rootUrl or sceneFilename for the scene to load\");\n}","typeGuard":null,"tryCatchPattern":"try {\n  await BABYLON.SceneLoader.ImportMeshAsync(\"\", rootUrl, fileName, scene);\n} catch (e) {\n  if ((e as Error).message.includes(\"valid scene filename\")) {\n    console.error(\"Empty rootUrl/sceneFilename — check path configuration\", { rootUrl, fileName });\n  }\n}","preventionTips":["Log/assert the resolved URL before loading to catch empty config values.","Centralize model path construction so defaults are never empty strings.","Validate config-derived paths at startup rather than at load time."],"tags":["loading","scene-loader","validation","url"],"backgroundTag":"missing-file-path","analyzedSha":"0592b347b8a4ee0236089ea86a749cacfdb266d8","analyzedAt":"2026-08-30T15:11:20.442Z","schemaVersion":2},"datasetVersion":"2026-08-30T18:17:15.746Z"}