In Studio 2022, I could connect to our TM Server in GroupShare with this code.

I used the Windows credentials of the current user without having to ask the user to enter them:

 private void button1_Click(object sender, EventArgs e)
 {
     bool blWindowsAuthentication;
     blWindowsAuthentication = true;

     // Connect with URL and credentials
     // TranslationProviderServer tmServer = new TranslationProviderServer(GetUri(txtServerURI.Text), blWindowsAuthentication, "", "");
     TranslationProviderServer tmServer = new TranslationProviderServer(GetUri("https://SERVERNAME"), blWindowsAuthentication, userName: null, password: null);
     MessageBox.Show ("Connected");
 }

 private Uri GetUri(string _serverUri)
 {
     return new Uri(_serverUri);
 }

Now exactly the same code gives this error:

System.NullReferenceException: 'Object reference not set to an instance of an object.'

Here is the stack trace with more details:

Source: Sdl.Desktop.Platform.ServerConnectionPlugin


StackTrace " at Sdl.Desktop.Platform.ServerConnectionPlugin.TMServer.InternalClients.TmServiceRestClientCreator.CreateRestClient(String baseAddress, ClientSettings clientSettings)
at Sdl.Desktop.Platform.ServerConnectionPlugin.TMServer.InternalClients.InternalRestClient..ctor(String baseAddress, ITmServiceRestClientCreator restClientCreator, IBcmToTransUnitConverter bcmToTransUnitConverter)
at Sdl.Desktop.Platform.ServerConnectionPlugin.TMServer.TranslationMemoryAdminstrationClientFactory.Create(String baseAddress, UserCredentials credentials, IServerConnectionService serverConnectionService)
at Sdl.LanguagePlatform.TranslationMemoryApi.TranslationProviderServer..ctor(Uri serverUri, Boolean useWindowsAuthentication, String userName, String password)\
at WindowsFormsApp1.Form1.button1_Click(Object sender, EventArgs e)

If I pass explictly the user name and password, then the connection works correctly but I would want to avoid asking the users for their Windows credentials. 

Is the implicit login not supported anymore?

According to the SDK, this should work:

https://developers.rws.com/studio-api-docs/api/translationmemory/Sdl.LanguagePlatform.TranslationMemoryApi.TranslationProviderServer.html
useWindowsAuthentication

Whether to use Windows authentication. When n set to false, userName and password have to be specified. When set to true , either pass null for userName and password in order to log on as the currently logged on Windows user, or set userName to a domain-qualified Windows user name and password to the matching password to log on using basic Windows authentication.

Thanks!

Daniel