> ## Documentation Index > Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Event Tracking Broken (core event stopped firing), PostHog > Event Tracking Broken (core event stopped firing) for PostHog stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it. **Card class:** [Hero](/nerve-centre/overview#card-classes-explained) • **Category:** [Analytics](/nerve-centre/connectors#connectors-by-type) ## At a glance > **Event Tracking Broken (core event stopped firing)** is a Nerve Centre alert tracked from PostHog event data. It fires when a designated core event, for example `purchase`, `add_to_cart`, or `checkout_started`, records zero occurrences for more than an hour. A single core event going silent is a precise, high-confidence sign that instrumentation broke on a specific flow, even when overall event volume still looks healthy. This is the most surgical of the tracking alarms. | | | | --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | | **What it counts** | Alert events raised when a core event's count stays at zero for more than one hour. | | **Sample type** | Backend API data from PostHog event counts, evaluated against the alert rule on each refresh. | | **Why it matters** | One broken event can hide a whole revenue flow while the rest of your dashboard looks normal. This alert isolates the exact event that stopped. | | **Reading the value** | A non-zero count means a core event went silent. Open the alert to see which event and when it last fired. | | **Currency** | count | | **Time window** | `RT` | | **Alert trigger** | `core event count = 0 for >1h` | | **Sentiment key** | `ph_alert_tracking_broken` | | **Roles** | owner, marketing | ## Calculation Calculated automatically from your PostHog data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading. ## Worked example *A representative reading of **Event Tracking Broken (core event stopped firing)** for a typical merchant on PostHog.* Suppose `purchase` normally fires 40 to 80 times an hour. After a checkout refactor on 18 Apr 26, the event handler is renamed and `purchase` records zero for two consecutive hours while `pageview` and `add_to_cart` keep flowing. The alert fires. Because only one event went dark, you can go straight to the checkout instrumentation rather than auditing the whole site. Cross-reference Core Events Firing to confirm which events are still healthy. For deeper investigation, use Vortex Mind to trace upstream causes; for natural-language exploration, ask Ask Viq. ## Sibling cards merchants should reference together | Card | Why merchants reach for it | | ------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------- | | [`ph_core_events_firing`](/nerve-centre/kpi-cards/posthog/core-events-firing) | Event Health sibling: the live count of core events still firing. | | [`ph_alert_event_volume_drop`](/nerve-centre/kpi-cards/posthog/event-volume-drop-25-vs-baseline) | Nerve Centre sibling: broad event volume collapse. | | [`ph_top_events`](/nerve-centre/kpi-cards/posthog/top-10-events-by-volume) | Event Health sibling: your highest-volume events. | | [`ph_event_volume`](/nerve-centre/kpi-cards/posthog/total-event-volume) | Executive sibling: total event volume. | | [`ph_health_score`](/nerve-centre/kpi-cards/posthog/posthog-tracking-health-score) | Executive sibling: overall tracking health score. | ## Reconciling against the vendor's own dashboard **Where to look in PostHog's own dashboard:** In PostHog, open the Activity or live events view and filter to the named core event. If it has not appeared for over an hour, the gap matches the alert. A trend insight on that single event, viewed hourly, makes the silence visible against its normal cadence. **Why the Vortex IQ value may legitimately differ:** | Reason | Direction | What to do | | ------------------------------------------------------------------------------------------------- | --------- | --------------------------------------------- | | **Event naming.** A rename ships the same action under a new event name; the old name reads zero. | Variable | Check for a renamed event firing in parallel. | | **Low-traffic hour.** A genuinely quiet event may hit zero overnight without being broken. | Variable | Confirm the event normally fires hourly. | | **Ingestion lag.** Brief ingestion delays can show a temporary zero that recovers. | Marginal | Re-check after the next refresh. | **Cross-connector reconciliation:** complement with sibling cards in the same category for the full diagnostic picture. For divergence investigations, use Vortex Mind. ## Known limitations / merchant FAQs **Q: How often does Event Tracking Broken (core event stopped firing) update?** The card refreshes on the standard data refresh (typically every 30-60 minutes for live integrations). For real-time signals, force a manual refresh from the dashboard. **Q: Which events count as core?** Core events are the ones you designate as business-critical, typically the steps in your primary funnel plus purchase. Configure the set so the alert watches what actually matters to revenue. **Q: It fired but the event is firing again. Why?** The event was silent for over an hour and then recovered, often after a deploy was rolled back or a renamed event was restored. The alert records the outage window even after recovery. **Q: Can I customise the alert threshold?** Yes, sensitivity thresholds are configurable per profile in the Sensitivity tab. Adjust to match your business baseline rather than relying on the generic default. *** ### Tracked live in Vortex IQ Nerve Centre *Event Tracking Broken (core event stopped firing)* is one of hundreds of KPI pulses Vortex IQ tracks across PostHog and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. [Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.