WebView2's ICoreWebView2CreateCoreWebView2ControllerCompletedHandler callback is never called when the process is running in a login screen

[ddbb2017]

I need to use the WebView2 control from a custom credential provider, written in C++. I'm using MSFT's Win32_GettingStarted sample as a test. I can build it in VS 2022 and it runs fine in a regular user desktop.

But if I use the same code from a custom credential provider (that runs in a secure desktop in the login screen) the WebView2 control remains blank. I did some investigation was able to see that in the following code snippet:

void CreateWebView(HWND hWnd)
{
	HRESULT hr;
	WCHAR buff[256];

	//Get temp folder
	WCHAR buffTmp[MAX_PATH] = {};
	GetTempPath(_countof(buffTmp), buffTmp);
	StringCchCat(buffTmp, _countof(buffTmp), L"WebView2GettingStarted\\");
	g_strTmpPath = buffTmp;

	// <-- WebView2 sample code starts here -->
	// Step 3 - Create a single WebView within the parent window
	// Locate the browser and set up the environment for WebView
	hr = CreateCoreWebView2EnvironmentWithOptions(nullptr, buffTmp, nullptr,
		Callback<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>(
			[hWnd](HRESULT result, ICoreWebView2Environment* env) -> HRESULT 
			{
				HRESULT hr2;

				// Create a CoreWebView2Controller and get the associated CoreWebView2 whose parent is the main window hWnd
				hr2 = env->CreateCoreWebView2Controller(hWnd, 
					Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
					[hWnd](HRESULT result, ICoreWebView2Controller* controller) -> HRESULT
					{
						HRESULT hr;

						MessageBox(
							NULL, L"ICoreWebView2CreateCoreWebView2ControllerCompletedHandler was called", 
                                                        L"Loaded_MsgBox",
							MB_OK);

						//Other code
						....

						return S_OK;
					}).Get());


				if(FAILED(hr2))
				{
					WCHAR buff[256] = {};
					StringCchPrintf(buff, _countof(buff), L"ERROR: (0x%x) CreateCoreWebView2Controller", hr2);
					MessageBox(NULL, buff, L"ERROR", MB_ICONERROR);
				}


				return S_OK;
			}).Get());


	if(FAILED(hr))
	{
		StringCchPrintf(buff, _countof(buff), L"ERROR: (0x%x) CreateCoreWebView2EnvironmentWithOptions", hr);
		MessageBox(NULL, buff, L"ERROR", MB_ICONERROR);
	}

    return hr;
}

The env->CreateCoreWebView2Controller call succeeds, but the ICoreWebView2CreateCoreWebView2ControllerCompletedHandler callback is never invoked (or my "Loaded_MsgBox" is never shown), so the HWND for the WebView2 remains blank.

There seems to be no errors or anything that I can find.

Moreover, when I close the process, this also causes a crash somewhere in the destructor in the EmbeddedBrowserWebView.dll.

The WebView2 itself is so huge, I don't even know where to begin approaching this.

Any idea how to make it work from the secure desktop?

[laultman]

My problem is similar to yours, I my code also fails in the callback, but my error is Procedure not found. I too have not been able to find anything to help locate the issue. Additionally, the EmbeddedBrowserWebView.dll.pdb cannot be found. I tried using the additional options to find the symbols but could not locate this information.