an error occurred trying to start process "rundll32." exe with working directory c:\Windows\System32 access is denied

[jh-mobitech]

an error occurred trying to start process "rundll32." exe with working directory c:\Windows\System32 access is denied

Get this error when use MAUI to call Google Auth:

#if WINDOWS
try
{
var result = await WinUIEx.WebAuthenticator.AuthenticateAsync(new Uri(authUrl), new Uri(redirectUri));
var authCode = result?.Properties["code"];
Console.WriteLine($"Google authCode：{authCode}");
string accessToken = await ExchangeCodeForAccessToken(authCode);
Console.WriteLine($"Google accessToken：{accessToken}");
Preferences.Set(CommenSetting.GoogleDriveAccessToken, accessToken);
return accessToken == null ? "" : accessToken;
}
catch (Exception ex)
{
_ = Application.Current?.MainPage?.DisplayAlert(Localization.Resources.title_alert, ex.Message, Localization.Resources.btn_ok);
Console.WriteLine($"Google Unknow Error：{ex.Message}");
return "";
}
#else

Any Idea?

[jh-mobitech]

[dotMorten]

It doesn’t appear to be a WinUIEx issue but do you have a reproducer app you can share? The above didn’t give much to go on

[jh-mobitech]

Thanks for your quick response.

Well, I just called

            try
            {
                var result = await WinUIEx.WebAuthenticator.AuthenticateAsync(new Uri(authUrl), new Uri(redirectUri));
            }
            catch (Exception ex)
            {
               _ = Application.Current?.MainPage?.DisplayAlert(Localization.Resources.title_alert, ex.Message, Localization.Resources.btn_ok);
                Console.WriteLine($"Google Unknow Error：{ex.Message}");
                return "";
            }

and then it goes to catch block and the error is

an error occurred trying to start process "rundll32." exe with working directory c:\Windows\System32 access is denied

It works in one Windows laptop but fails in a new laptop.

try to run VS as Adminitrator but also not works. It is a MAUI project and happens when I debugging the code.

[jh-mobitech]

I checked the source code and it did try to open rundll32.exe there.

Do you have any suggestion why this happen? Thanks.

[dotMorten]

I see. That’s odd. Must be some odd security configuration that machine has. If you figure out what setting causes it I would love to know

[jh-mobitech]

OK, Can't find out the cause so wonder if I can get any help form you.

Anyway, Thanks. Will update here if I solved it.

[dotMorten]

Sorry never seen this before or know why this is failing to launch

[dotMorten]

What if you run that bit of code to launch the browser from a little console app or something else. Do you see the same thing happening there on that machine? It's a pretty standard way to launch the default browser on Windows.