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Subscriber growth alerts

Warns when an event's subscriber count keeps growing beyond a threshold — similar to Node.js MaxListenersExceededWarning. Helps spot missing -= in OnDestroy / OnDisable.

How it works

A warning fires when both are true:

  1. Subscriber count for an event bucket (OwnerType::EventName) is above the threshold (default 10)
  2. Count increased on each of the last N consecutive subscribes (default 3 — reduces false positives from scene-load spikes)

Unsubscribes that drop count below the threshold re-arm the warning for that event.

Where to find them

  • Growth Alerts tab — settings + recent warnings list
  • Unity Console — [EventMonitor] Subscriber growth alert: … (when enabled)
  • Stats tab title may include alert count alongside leak count

Settings

On the Growth Alerts tab (persisted via EditorPrefs):

SettingDefaultMeaning
Warnings enabledONMaster switch
Threshold10Subscriber count that must be exceeded
Min growth streak3Consecutive growth subscribes before warning

Tips

  • Legitimate fan-out (e.g. UI pooling many listeners) may trigger alerts — raise threshold or disable warnings for that project phase
  • Pair with Leak detection (Stats tab) for destroyed-object leaks vs runaway growth

Event Monitor — Unity Editor documentation