What causes "target requires a selector or x/y coordinates" in wailsapp/wails?

Profile and reduce peak memory before the COM-using code runs; free large buffers and caches.

target requires a selector or x/y coordinates

Error message

target requires a selector or x/y coordinates

What it means

CoInitializeEx initializes COM on a thread; E_OUTOFMEMORY means the runtime could not allocate what it needs to initialize. The w32 wrapper panics with 'CoInitializeEx failed with E_OUTOFMEMORY' for this HRESULT. It is rare and almost always reflects genuine memory exhaustion or commit-limit pressure on the process rather than API misuse — the flags and thread state were acceptable, allocation simply failed.

Source

Thrown at v3/pkg/application/mcp_inject.js:303

    // scrolling selector targets into view first.
    async function resolveTarget(target) {
        if (target && target.selector) {
            const el = document.querySelector(target.selector);
            if (!el) throw new Error('no element matches selector: ' + target.selector);
            el.scrollIntoView({ block: 'center', inline: 'center', behavior: 'instant' });
            await nextFrame();
            const rect = el.getBoundingClientRect();
            if (rect.width === 0 && rect.height === 0) {
                throw new Error('element has zero size (is it hidden?): ' + target.selector);
            }
            const point = clampToViewport(rect.x + rect.width / 2, rect.y + rect.height / 2);
            return { x: Math.round(point.x), y: Math.round(point.y), el };
        }
        if (target && typeof target.x === 'number' && typeof target.y === 'number') {
            const point = clampToViewport(target.x, target.y);
            return { x: Math.round(point.x), y: Math.round(point.y), el: null };
        }
        throw new Error('target requires a selector or x/y coordinates');
    }

    const BUTTONS = { left: 0, middle: 1, right: 2 };
    const BUTTON_MASKS = { 0: 1, 1: 4, 2: 2 };

    function focusTarget(el) {
        const focusable = el && el.closest
            ? el.closest('input, textarea, select, button, a[href], [tabindex], [contenteditable]')
            : null;
        if (focusable && typeof focusable.focus === 'function') {
            focusable.focus();
            return focusable;
        }
        if (document.activeElement && document.activeElement !== document.body) {
            document.activeElement.blur();
        }
        return null;
    }

View on GitHub (pinned to 0e754b1b40)

Solutions

Profile and reduce peak memory before the COM-using code runs; free large buffers and caches.
Check whether the process runs under a job object/container memory cap and raise it if legitimate.
On 32-bit builds, build 64-bit to remove address-space pressure.
Look for interface leaks (missing Release via syscall on the vtable) that accumulate over long sessions.
If graceful degradation matters, recover() around the init and retry after freeing memory.

Example fix

// before
bigCache := loadEverything() // fills commit limit
CoInitializeEx(COINIT_APARTMENTTHREADED) // E_OUTOFMEMORY panic

// after
bigCache := loadBudgeted(allocLimit)
debug.FreeOSMemory()
CoInitializeEx(COINIT_APARTMENTTHREADED)

Defensive patterns

Strategy: fallback

Try / catch

func initCOMWithRetry(flags uintptr) (err error) {
	for i := 0; i < 2; i++ {
		func() {
			defer func() {
				if r := recover(); r != nil {
					if msg, _ := r.(string); strings.Contains(msg, "E_OUTOFMEMORY") {
						debug.FreeOSMemory()
						err = fmt.Errorf("com init oom (attempt %d)", i)
						return
					}
					panic(r)
				}
			}()
			CoInitializeEx(flags)
			err = nil
		}()
		if err == nil {
			return nil
		}
	}
	return err
}

Prevention

Reduce peak memory before COM-heavy phases.
Watch for COM interface leaks (missing Release) in long sessions.
Raise job-object/container memory caps if legitimately needed.

When it happens

Trigger: Initializing COM on a thread after the process has allocated most of its commit limit (huge images, unbounded caches); running under a job object with a memory cap so COM's per-thread allocations fail; 32-bit process near the address-space ceiling.

Common situations: A background worker goroutine calling into COM-using features (taskbar, dialogs) after an image-heavy operation has filled memory; containers/job objects with hard memory limits; leak of COM interfaces slowly consuming memory until init fails.

Related errors

AI-assisted analysis of wailsapp/wails@0e754b1b40 (2026-08-15). Data as JSON: /api/errors/37d6a92ca59dbe73. Report an issue: GitHub.