Commented Unassigned: computername\username Access denied [12373]

Hi,

Since version Release 2.5.17 I'm unable to schedule a task using "computername\username"
This worked in version Release 2.4.2

Example:
Computer is Lan
User is LanUser

Please note that it's a local admin account (not domain)
Trying to log in with Lan\LanUser fails with "Access is denied"
Comments: ** Comment from web user: BertDM **

That worked (my project is 4.0)

However I'm getting a new error now:
Some or all identity references could not be translated.

This happens when there is a null value for parameter sddlForm
Stacktrace:
at System.Security.Principal.NTAccount.Translate(IdentityReferenceCollection sourceAccounts, Type targetType, Boolean forceSuccess)
at System.Security.Principal.NTAccount.Translate(Type targetType)
at Microsoft.Win32.TaskScheduler.User..ctor(String userName)
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String Path, TaskDefinition definition, TaskCreation createType, String UserId, String password, TaskLogonType LogonType, String sddl)
at Tester(String hostname, Action scanFinished, String login, String password)