{"record":{"id":"fe6ea8e2f872481a","repo":"langflow-ai/langflow","slug":"an-internal-error-occurred-while-creating-the-flow","errorCode":null,"errorMessage":"An internal error occurred while creating the flow.","messagePattern":"An internal error occurred while creating the flow\\.","errorType":"http","errorClass":"HTTPException","httpStatus":500,"severity":"error","filePath":"src/backend/base/langflow/api/v1/flows_helpers.py","lineNumber":354,"sourceCode":"        if effective_id is not None:\n            db_flow.id = effective_id\n\n        db_flow.updated_at = datetime.now(timezone.utc)\n        await _validate_and_assign_folder(session, db_flow, user_id)\n\n        session.add(db_flow)\n        await session.flush()\n        await session.refresh(db_flow)\n        await _save_flow_to_fs(db_flow, user_id, storage_service)\n\n        return FlowRead.model_validate(db_flow, from_attributes=True)\n    except Exception as e:\n        if hasattr(e, \"errors\"):\n            raise HTTPException(status_code=400, detail=str(e)) from e\n        if isinstance(e, HTTPException):\n            raise\n        logger.exception(\"Error creating flow\")\n        raise HTTPException(status_code=500, detail=\"An internal error occurred while creating the flow.\") from e\n\n\nasync def _read_flow(\n    session: AsyncSession,\n    flow_id: UUID,\n    user_id: UUID,\n):\n    \"\"\"Read a flow.\n\n    When the registered authorization service supports cross-user fetch\n    (authorization plugin), the row is loaded by id alone and the caller's\n    ``ensure_flow_permission`` decides access. Otherwise the query stays\n    owner-scoped so the OSS pass-through default cannot widen visibility.\n    \"\"\"\n    from langflow.services.authorization.fetch import authorized_or_owner_scoped\n\n    return await authorized_or_owner_scoped(\n        session,","sourceCodeStart":336,"sourceCodeEnd":372,"githubUrl":"https://github.com/langflow-ai/langflow/blob/976ec789d2886a86de109c044d089d68e96c9a35/src/backend/base/langflow/api/v1/flows_helpers.py#L336-L372","documentation":"HTTP 500 catch-all in _create_flow: an unexpected, non-validation, non-HTTP exception escaped flow creation (DB errors during flush/refresh, filesystem failure not wrapped earlier, programming errors). The real traceback goes to logger.exception(\"Error creating flow\"); the client gets a generic message so internals are not leaked.","triggerScenarios":"Database down or constraint violation not surfaced as IntegrityError earlier (race on unique endpoint_name), flush failing on serialization of a column, _save_flow_to_fs raising an unexpected non-OSError, or a bug in a create-path hook.","commonSituations":"DB connection dropped mid-request; two concurrent creates racing on a unique index; a schema/code version mismatch after a partial upgrade (migration not applied); exotic fs_path errors that bypass the OSError branch.","solutions":["Read the server log around 'Error creating flow' — the logged traceback names the root cause; the HTTP message is intentionally generic.","Apply pending migrations (make alembic-upgrade) after upgrades.","For race conditions on endpoint_name, retry with a unique name or after the conflicting request commits.","Verify DB connectivity and that the flows table schema matches the models."],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"try { await createFlow(body) } catch (e) { if (e.status === 500) { checkServerLog('Error creating flow'); retryOnceAfterDbCheck(); } }","preventionTips":["Run migrations after every upgrade","Keep DB connections healthy (pool timeouts)","Check server logs — the client detail is generic by design"],"tags":["http-500","database","flows","logging"],"backgroundTag":null,"analyzedSha":"976ec789d2886a86de109c044d089d68e96c9a35","analyzedAt":"2026-08-14T18:23:12.227Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}