Hello Michel van den Brink,
first thanks for your Reply.
I tried that. Sadly the Login still doesn't work.
Error Message in the log:
Source : Microsoft.IdentityModel.Clients.ActiveDirectory
Method : RunAsyncTask
Date : 01.03.2018
Time : 09:11:10
Error : unknown_user_type: Unknown User Type
Stack Trace : bei Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext.RunAsyncTask[T](Task`1 task)
bei Microsoft.Xrm.Tooling.Connector.CrmWebSvc.ObtainAccessToken(AuthenticationContext authenticationcontext, String resource, String clientId, ClientCredentials clientCredentials)
bei Microsoft.Xrm.Tooling.Connector.CrmWebSvc.ExecuteAuthenticateServiceProcess(Uri serviceUrl, ClientCredentials clientCredentials, UserIdentifier user, String clientId, Uri redirectUri, PromptBehavior promptBehavior, String tokenCachePath, Boolean isOnPrem, String authority, Uri& targetServiceUrl, AuthenticationContext& authContext, String& resource)
bei Microsoft.Xrm.Tooling.Connector.CrmWebSvc.DiscoverOrganizations(Uri discoveryServiceUri, ClientCredentials clientCredentials, UserIdentifier user, String clientId, Uri redirectUri, PromptBehavior promptBehavior, String tokenCachePath, Boolean isOnPrem, String authority)
bei Microsoft.Xrm.Tooling.CrmConnectControl.CrmConnectionManager.QueryOAuthDiscoveryServer(Uri discoServer, ClientCredentials liveCreds, UserIdentifier user, String clientId, Uri redirectUri, PromptBehavior promptBehavior, String tokenCachePath)
bei Microsoft.Xrm.Tooling.CrmConnectControl.CrmConnectionManager.FindCrmOnlineDiscoveryServer(ClientCredentials liveCreds)
bei Microsoft.Xrm.Tooling.CrmConnectControl.CrmConnectionManager.ValidateServerConnection(CrmOrgByServer selectedOrg)