# `Mob.Screen.UnhandledEventError`
[🔗](https://github.com/genericjam/mob/blob/master/lib/mob/screen/unhandled_event_error.ex#L1)

Raised by the `handle_event/3` `use Mob.Screen` injects when a screen defines
no clause for an event.

A distinct exception rather than a `RuntimeError` with a recognisable message,
because `Mob.Agent.Receipt` has to tell "this event matched nothing" apart
from "the handler crashed" in order to attribute the first to event routing
and the second to application code. Matching on message text would break the
moment the wording changed.

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