Hello.
Thank you for reporting this.

After some investigation, here is what is happening:

1. Recently, we have updated our public demo server with a new version (from OPC Foundation).
2. As it turns out, this new version, most likely intentionally, provides a value for the node in our example that is actually invalid. More specifically, there is a structure field which contains an array of Variant-s, and one of the array elements is an ExtensionObject with unknown (undefined) TypeId. This can be verified e.g. in UaExpert, where it shows "Unknown Extension Object":
 
3. QuickOPC cannot decode the value (neither can anybody else) and returns an error (for the whole Read or Subscribe).

This QuickOPC behavior is by design. However, it now breaks some of our examples that were intended to succeed. For this reason, as much as I do not like it, we have changed the behavior to be "relaxed" in this case. Instead of failing the whole conversion, we will let it succeed, and the structure field that cannot be converted will instead contain an instance of PrimitiveData with an undecoded ExtensionObject as its value.

The change is in QuickOPC 5.83.1134 (now on our Web page and in the package repositories).

Best regards
 

Hello, when I try to run the example "Examples - OPC UA Complex Data - Read a value" found on your knowledge base I always get the exception
 "No nodes returned when browsing the OPC-UA server for a single node (no match)." when i call the ReadValue method from the opcua client
I haven't changed anything from your code.
Thank you

Here is the code: // Define which server and node we will work with.
UAEndpointDescriptor endpointDescriptor =
"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
// or " opcua.demo-this.com:51211/UA/SampleServer " (currently not supported)
// or " opcua.demo-this.com:51212/UA/SampleServer/ "
UANodeDescriptor nodeDescriptor =
"nsu=http://test.org/UA/Data/ ;i=10239"; // [ObjectsFolder]/Data.Static.Scalar.StructureValue

// Instantiate the client object.
var client = new EasyUAClient();

// Read a node which returns complex data. This is done in the same way as regular reads - just the data
// returned is different.
object value;
try
{
value = client.ReadValue(endpointDescriptor, nodeDescriptor);
}
catch (UAException uaException)
{
Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
return;
}