wailsapp/wails · error

CoCreateInstance failed with E_INVALIDARG

Error message

CoCreateInstance failed with E_INVALIDARG

What it means

Error "CoCreateInstance failed with E_INVALIDARG" thrown in wailsapp/wails.

Source

Thrown at v3/pkg/w32/ole32.go:64

func CoInitialize() {
	procCoInitialize.Call(0)
}

func CoUninitialize() {
	procCoUninitialize.Call()
}

func CoCreateInstance(clsid *syscall.GUID, dwClsContext uintptr, riid *syscall.GUID, ppv uintptr) HRESULT {
	ret, _, _ := procCoCreateInstance.Call(
		uintptr(unsafe.Pointer(clsid)),
		0,
		uintptr(dwClsContext),
		uintptr(unsafe.Pointer(riid)),
		uintptr(ppv))

	switch uint32(ret) {
	case E_INVALIDARG:
		panic("CoCreateInstance failed with E_INVALIDARG")
	case E_OUTOFMEMORY:
		panic("CoCreateInstance failed with E_OUTOFMEMORY")
	case E_UNEXPECTED:
		panic("CoCreateInstance failed with E_UNEXPECTED")
	}

	return HRESULT(ret)
}

func CreateStreamOnHGlobal(hGlobal HGLOBAL, fDeleteOnRelease bool) *IStream {
	stream := new(IStream)
	ret, _, _ := procCreateStreamOnHGlobal.Call(
		uintptr(hGlobal),
		uintptr(BoolToBOOL(fDeleteOnRelease)),
		uintptr(unsafe.Pointer(&stream)))

	switch uint32(ret) {
	case E_INVALIDARG:

View on GitHub (pinned to 0e754b1b40)

Solutions

1. Check all pointer arguments to CoCreateInstance: clsid and riid must be valid GUID pointers and ppv must be a valid output pointer; a null or malformed argument yields E_INVALIDARG.
2. Use a valid class context such as CLSCTX_INPROC_SERVER or CLSCTX_LOCAL_SERVER for dwClsContext.

When it happens

Trigger: Occurs when CoCreateInstance returns E_INVALIDARG, typically due to an invalid class/interface identifier or invalid creation flags.

Common situations: See trigger scenarios.

AI-assisted analysis of wailsapp/wails@0e754b1b40 (2026-08-15). Data as JSON: /api/errors/0861e606749b6fd5. Report an issue: GitHub.