# `Chronicle.Observers.MultipleGenerationsOfEventTypeInObserver`
[🔗](https://github.com/Cratis/Chronicle.Elixir/blob/main/lib/chronicle/observers/multiple_generations_of_event_type_in_observer.ex#L4)

Raised when an observer with pinned generation delivery handles several generations of
the same event type.

With pinned generation delivery, Chronicle must send each generation to exactly one
handled event type module; handling two generations of the same id makes that ambiguous.

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*Consult [api-reference.md](api-reference.md) for complete listing*