This is a different error from where you posted, so I have splitted the thread and created a new one.
Error -1073479673 corresponds to:
// The item ID is not defined in the server address space or no longer exists in the server address space.
and is reported by the target OPC server. Usually it means that the Item ID you pass to the server is correct syntactically (according to server rules), but cannot be found in its configuration.
I will agree that this error says all and nothing. In most cases so far, the problem has been somewhat self-describing. Up til now. for simplify I worked through some methods, collectings and so (to fit our system needs) on a Console application. Now I move the focus to a web application and from no-where I got this error. -1073479673 "OPC operation failure". Of course, the code are still functioning from the console application (referring same assemblies).
The console app, opc-server & also the debugging-web-server are located on same machine. I feel this should be some kind of security concern (like that webserver and console app may run as different users) but not sure where to start (or if there are anything else to do).
Thank's in advanced,