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Troubleshooting

Common issues and solutions for using Latch‑X effectively. If you don't find your issue here, search the docs or contact support.

Quick diagnostic checklist

Run this first

  • Read the error text carefully (it usually tells you the failing rule).
  • Validate the model validate button.
  • Try a minimal model to isolate the issue: yaml root: A components: A: { type: normal, mttf: 1000, mttr: 1 } dependencies: {}
  • Check tier & limits (Safety Limits).
  • Restart session (log out/in) and retry once.
  • Try another browser / clear cache & cookies.

Analysis issues

Analysis fails or times out

Symptoms - Analysis never completes - Long wait with no progress. - “Resource limit exceeded” messages.

Likely causes & fixes

Check these

  • Model too large: See Safety Limits for your tier. Simplify (fewer nodes/edges, more hierarchy) or upgrade.
  • Network/session issues: Refresh or re‑authenticate.
  • Timeout limits reached Retry with lower sim parameters.

BN vs MC results don’t match

Symptoms - Different availabilities / downtimes. - Different critical contributors.

Checklist

Align assumptions

  • Repair mode: BN “availability” assumes repairable steady‑state; MC uses temporal simulation. Set repair_enabled consistently.
  • Time horizon: simulation_time drives MC runs and BN reporting (e.g., expected downtime).
  • Randomness: MC has variance. Increase simulation_runs (1,000 → 10,000) and set a random_seed for comparison.

Unexpected analysis results

Symptoms - Availability values seem too high/low. - Critical components show minimal impact.

Steps

Try this

  • Parameter sanity: Recheck MTTF/MTTR magnitudes and units.
  • Dependency correctness: Confirm the intended AND/OR/quorum structure (see Dependencies).
  • Risk modeling: If using prob on risk nodes, remember it means P(UP) = “risk does not materialize”.
  • Sensitivity Explorer: Force single components DOWN to check impact.
  • Simplify & compare: Remove tiers until numbers make sense, then re‑add.

Slow performance

Symptoms - Analysis is much slower than expected.

Optimization

Speed it up

  • Reduce MC runs for iteration (100–1,000) and scale for final.
  • Prefer BN for quick structural validation; switch to MC for temporal/RTO.
  • Layer logic: Use hierarchical logical nodes rather than huge flat gates.
  • Prune model: Remove non‑critical nodes during exploration.
  • Check Latches" Latches can be significant contributor to the number of generated events.
  • Low MTTF/MTTR " Extremely Low MTTF/MTTR can be significant contributor to the number of generated events

Model creation issues

Component validation errors

Common messages & fixes

Fixes

  • “MTTF must be positive” → ensure values > 0 (in hours).
  • “Use prob OR mttf+mttr” → pick one approach for normals.
  • “sigma required for norm/lognorm” → add sigma.
  • “max_delay required for latch with mttf” → add max_delay.
  • “Unknown type” → valid types are normal | logical | latch.
  • “Duplicate component name” → choose a unique name.

Dependency issues

Common problems

Don’t do this

  • Circular dependency detected → refactor.
  • Invalid dependency target (name not in components) → fix typo / add component.
  • Multiple dep types on same target → split into layered logical nodes.
  • and/or/n_of_k on a normal target → use a logical target instead.
  • n_of_k with invalid n → ensure 1 ≤ n ≤ len(inputs).

Use the graph - Open diagram view to spot cycles, orphans, and overly dense hubs.

YAML parsing/import errors

Symptoms - Import fails; parser errors; model won’t load.

Fixes

YAML hygiene

  • Use spaces, not tabs; consistent indentation (2 spaces recommended).
  • Avoid duplicate keys in the same map.
  • Ensure lists are properly indented: ```yaml do: [a, b] # or do:
    • a
    • b ```
  • Validate with any YAML linter if in doubt.

Model integrity (signing)

Errors - “hashblock invalid” / “signature mismatch”.

Fixes - Re‑validate the model to regenerate the signature. - Ensure no background edits modified the file between save and upload.

Graph & UI issues

Diagram not rendering / blank SVG

Causes & fixes - Cache: Login/Logout.

Saving & autosave

Symptoms - Changes don’t persist; “Save failed”.

Fixes - Check connectivity; wait for autosave indicator to finish. - Manually Export YAML as a backup; re‑import if needed. - Avoid closing the tab during save operations.

Login & access

Symptoms - Session expires quickly; features greyed out.

Fixes - Clear cookies for the site and sign in again. - Check your tier and active limits (feature gating). - Try another browser / incognito session.

LLM Assistant issues

Model generation / editing via LLM

Common issues - Output too generic or overly complex. - Wrong component types, parameters, or dependency style. - Missing critical elements.

Improve results

Prompting checklist

  • Provide context: system overview, major tiers, constraints.
  • Be specific: list components, known MTTF/MTTR or prob, failover expectations.
  • State targets: simulation_time, target_availability, target_rto, repair_enabled.
  • Iterate: generate a minimal skeleton first, then refine.
  • Use higher tier AI model try the prompt with higher AI model (costs more units)

Always check if AI generated models meet your criteria.

Reporting issues

What to include

Technical details - Browser and version, OS, time of occurrence. - Exact error text and screenshots. - Account tier/subscription; current model size (nodes/edges).

Context - What you attempted; steps to reproduce. - Expected vs actual behavior. - Relevant YAML snippet (prefer a minimal reproducer).

Prevention tips

  • Build incrementally; validate at each step.
  • Export YAML backups regularly.
  • Keep units consistent (hours everywhere).
  • Use hierarchical logical nodes; avoid mixing dep types per target.
  • Set simulation_time to match SLA reporting.
  • Start MC with smaller simulation_runs; scale as needed.

More help