Error5 reports
Fix ValidationError
in RAGAS
✅ Solution
ValidationError in Ragas often arises when the output format of your language model (LLM) doesn't match the expected schema defined by a metric or Ragas component, like expecting "text" but receiving a JSON object. To fix this, carefully inspect the output schema expected by the failing component in the Ragas documentation or source code and adjust your LLM prompt to strictly adhere to that format, ensuring it returns the precise data structure and field names. If parsing JSON, ensure it is valid and decodable.
Related Issues
Real GitHub issues where developers encountered this error:
fix(metrics): @metric decorator drops user kwargs when pydantic model creation failsJul 31, 2026
fix(prompt): generate_multiple skips on_chain_error for ValidationError and OutputParserExceptionJul 22, 2026
fix(analytics): centralise safe model-attribute coercion for EmbeddingUsageEventJul 14, 2026
EmbeddingUsageEvent telemetry NaNs a metric when embeddings expose a non-string .model (e.g. fastembed)Jun 23, 2026
answer_correctness fails with OutputParserException: expected "text" but got "statements"`Aug 12, 2025
Timeline
First reported:Aug 12, 2025
Last reported:Jul 31, 2026