Problem with NavUserPassword connection type

marcomostacchi

I installed Nav 2016 on a server and I created an instance that with the Windows authentication works. There's not domain, so I set NavUserPassword as the connection type. The application runs, but when I try to open Nav there is a "Server Not Found" error in any case still runs instance. In the event viewer there is a notice that says:

The service has been able to add service principal names, because the service account was not found in Active Directory.
Account: SERVICE NT AUTHORITY \ NETWORK