internal error: accesskit adapter must exist when window exi

Error message

internal error: accesskit adapter must exist when window exists

What it means

Error "internal error: accesskit adapter must exist when window exists" thrown in slint-ui/slint.

Source

Thrown at internal/backends/winit/event_loop.rs:206

                EventResult::PreventDefault
            ) {
                return;
            }

            if let Some(mut window_event_filter) = window.window_event_filter.take() {
                let event_result = window_event_filter(window.window(), &event);
                window.window_event_filter.set(Some(window_event_filter));

                match event_result {
                    EventResult::PreventDefault => return,
                    EventResult::Propagate => (),
                }
            }

            #[cfg(enable_accesskit)]
            window
                .accesskit_adapter()
                .expect("internal error: accesskit adapter must exist when window exists")
                .borrow_mut()
                .process_event(&winit_window, &event);
        } else {
            return;
        }

        let runtime_window = WindowInner::from_pub(window.window());
        self.maybe_set_custom_cursor(&window, event_loop);
        if !matches!(event, WindowEvent::CursorMoved { .. } | WindowEvent::AxisMotion { .. }) {
            self.flush_pending_mouse_move();
        }

        match event {
            WindowEvent::RedrawRequested => {
                self.loop_error = window.draw().err();
            }
            WindowEvent::Resized(size) => {
                self.loop_error = window.resize_event(size).err();

View on GitHub (pinned to 3fd8f2ec03)

Solutions

Internal error: ensure accesskit is enabled when the window is created.
Report this with a reproducible case if it occurs in normal use.

When it happens

Trigger: Thrown at internal/backends/winit/event_loop.rs:206 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of slint-ui/slint@3fd8f2ec03 (2026-08-19). Data as JSON: /api/errors/c89cb0c3c3731852. Report an issue: GitHub.