# X_ISLAND_DISPOSER_MISSING

## Means

an island's mount returns no disposer

## Typical cause

an .island.tsx mount() is typed void or returns nothing, so the client router cannot dispose it on navigation and its listeners, hotkeys and live reads stay registered

## Fix

`x verify --only boundaries --json` — names the file; end its `mount()` with `return render(() => <Island {...props} />, el)`, the disposer the client router calls on navigation

[CLI and verify](/error-codes#cli-and-verify)