C# app throws error when connecting to indesign server

It throws this exception:

Invalid syntax (Exception from HRESULT: 0x800401E4 (MK_E_SYNTAX))
   at System.Runtime.InteropServices.Marshal.MkParseDisplayName(IBindCtx pbc, String szUserName, UInt32& pchEaten, IMoniker& ppmk)
   at System.Runtime.InteropServices.Marshal.BindToMoniker(String monikerName)

Caused by this line:

InDesignServer.Application app = (InDesignServer.Application)(System.Runtime.InteropServices.Marshal.B indToMoniker("configuration_noport"));

The server is successfully running with the no configuration parameters therefore the configuration name by default should be "configuration_noport".

Any idea why it's throwing this error? This is a C# 4.0 console application connecting to Indesign Server CS 5 (7.0).