Symptoms

When accessing smartforms Designer, I'm getting the error message below in the event log. In the browser it says "Authentication failed: The target principal is incorrect"

Exception information:
Exception type: AuthenticationException
Exception message: Authentication Failed : The target principal name is incorrect
at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.WindowsAuthentication(SCConnectionStringBuilder connectionStringBuilder)
at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.Authenticate(String connectionString)
at SourceCode.Security.Claims.Web.Shared.ConnectionClass.HandleIdentityImpersonation(Boolean asAppPool, Action action)
at SourceCode.Security.Claims.Web.Shared.ConnectionClass.TryCredentialToken(BaseAPIConnection connection, String credentialToken, Boolean asAppPool)
at SourceCode.Security.Claims.Web.Shared.ConnectionClass.GetPoolConnection(String credentialToken, Boolean asAppPool, Booleanand tokenApplied)
at SourceCode.Security.Claims.Web.Shared.ConnectionClass.Connect(BaseAPI baseAPI, Boolean asAppPool, Boolean validateLicense)
at SourceCode.Security.Claims.Web._trust.login.Page_Load(Object sender, EventArgs e)
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

 

Diagnoses

The issue was caused by incorrect Kerberos configuration in this environment.
 

Resolution

Since the environment is not configured for Kerberos, removing all SPNs set for K2 Service account forcing K2 to use Pass-through authentication resolved the issue.