I’m very new to Navision, but I’d like to authenticate a Navision user with .NET to check their credentials are valid (in C# or VB.NET) through the service tier. Is this possible?
I don’t know about through the service tier, but you can definitely retrieve the current user’s SID and compare it to the Windows Login table to make sure it exists.
You could also write a small Codeunit in NAV that does this and expose it as a Web Service that your .NET app can connect to. That is technically through the service tier.