HKUDS/DeepTutor · error · GenerationFailure

interactive html failed validation: {validation_error}

Error message

interactive html failed validation: {validation_error}

What it means

After InteractiveGenerator returns HTML code, the block validates it with validate_visualization(code, 'html'). If the generated HTML fails validation (syntax/structure rules), GenerationFailure is raised with the specific validation error.

Source

Thrown at deeptutor/book/blocks/interactive.py:96

                language=ctx.language,
            )
            analysis = await pipeline.run_analysis(
                user_input=user_input,
                history_context=history_context,
                render_mode="html",
            )
            code = await pipeline.run_code_generation(
                user_input=user_input,
                history_context=history_context,
                analysis=analysis,
            )
        except Exception as exc:
            logger.warning(f"InteractiveGenerator failed: {exc}", exc_info=True)
            raise GenerationFailure(f"interactive generation failed: {exc}") from exc

        ok, validation_error = validate_visualization(code, "html")
        if not ok:
            raise GenerationFailure(f"interactive html failed validation: {validation_error}")

        return (
            {
                "render_type": "html",
                "code": {"language": "html", "content": code},
                "description": analysis.description,
                "chart_type": analysis.chart_type,
            },
            [],
            {
                "review_changed": False,
                "review_notes": "Passed local validation.",
            },
        )


__all__ = ["InteractiveGenerator"]

View on GitHub (pinned to 3e82f13042)

Solutions

1. Read validation_error to find the offending construct in the HTML
2. Retry, possibly with higher max_tokens so output isn't truncated
3. Use a stronger model or simplify the requested interactive widget
4. If persistent, hand-edit or externally supply the HTML

def plausible_html(code: str) -> bool:
    return bool(code) and code.lstrip().lower().startswith('<!doctype') or '<html' in code.lower()

try:
    return await interactive_block.generate(ctx)
except GenerationFailure as exc:
    if 'failed validation' in str(exc):
        return await interactive_block.generate(ctx)  # retry once
    raise

When it happens

Trigger: Calling interactive _generate when the generated HTML string fails validate_visualization — e.g. unbalanced tags, script syntax errors, or whatever structural rules the 'html' validator enforces.

Common situations: LLM emits truncated HTML due to max-token limits; broken inline <script> JS; validator tightened in a newer version; model too weak for large interactive documents.

Related errors

• interactive generation failed: {exc}
• Model not configured for agent {self.agent_name}. Please act
• Render failed because local LaTeX is missing. Please avoid T
• Document not found
• Unsupported import source: {value!r}

AI-assisted analysis of HKUDS/DeepTutor@3e82f13042 (2026-08-27). Data as JSON: /api/errors/2cf4e3af6786f124. Report an issue: GitHub.