Hi, yesterday evening I added a Quick Reply with some more infos, but it got lost.
They were:
1) Tried to comment the foreach loop, the app went on and PLC communication started. We had some readings and writings (more or less 1/sec) for about 10/15 second, then crashed again. I repated the same test 3 times.
2) Upgraded app to .Net Framework 4.7.1 and QuickOPC 2020.2 (last versione available I found) and reapeated the test: same result, crash after 10/15 second after communication started.

Yesterday evening I downgraded Windows back to version 1909.

This morning repeated the test, with "old" app (.Net 4.6.2 and QuickOPC 2018.3) and "new" one (.Net 4.7.1 and QuickOPC 2020.2): everything is working fine.
It is sure that the first cause is something changed in Windows 10 vers.2004 and we will warn our custmer not to upgrade Windows for the moment, but we have to solve the issue for future compatibility.

One info for you: from this point of view (Windnows version) nothing change from QuickOPC 2018.3 and newer version, 2020.2 too.

On my side, next week I will made some more trials:
1) The one suggested (makeing a simple test app)
2) Try to use app with OPC communication disabled (it can work also without connection) to see that the problem is not on our code.

The problem is that I have to prepare a new PC with newer Windows, I turned back my Windows version and i will not upgrade until solution.

Hello, is there any way to discover if the problem is "related to BoxedApp SDK"? Or some other suggestions?
I tried the workarounds explained in the link, but with the same result: app crash.

To give more detailed infos:
- The crash happens when accessing UANodeElement in a foreach loop on the UANodeElementCollection returned by the EasyUAClient.BrowseObjects(...)
- The call to BrowseObjects returns correctly
- In a try/catch block there is the call to BrowseObjects and a foreach loop the logs objects infos returned
- in the loop, non exception is catched (in debug mode) and the app crashes (returns to IDE abruptly)
If in Realese Mode the app crashes and an error is logged in Windows Event Log

Example code crashing:

EasyUAClient clientOPCUA = new EasyUAClient();
UAEndpointDescriptor uadesc = new UAEndpointDescriptor();

uadesc.UrlString = host;
UANodeElementCollection uaElColl = clientOPCUA.BrowseObjects(uadesc);
foreach (UANodeElement item in uaElColl)
{
//Crashes in one of the following statements, may vary the exact statement
Console.WriteLine("OPCCHN - OPC browse node:" + item.ToString());
Console.WriteLine("OPCCHN - OPC browse node display name:" + item.DisplayName);
Console.WriteLine("OPCCHN - OPC browse node path:" + item.BrowsePath.ToString());
Console.WriteLine("OPCCHN - OPC browse node ID:" + item.NodeId.ToString());
}

Hi, we area using EasyUAClient since 4 years without any problems on Windows 7 and Windows 10 machines (about 100).
Some days ago we upgraded a Win10Pro machine with version 1909 to version 2004 and QuinckOPC stopped to execute with exception 0xCFFFFFFFF.
No way to make it work.

I tried to upgrade also a developing machine (C# with Visual Studio 2017) from vers.1909 to 2004. In debugging mode the app crashes and VIsual Studio stops running app without any notice/tracing.
On machine with Windows 10 Pro vers. 1909 everything is working fine.

At the moment we are using library vers. 2018.3. We have not yet tried to use a more recent version because our app is not fully compatible with .NET framework 4.7. and requires some modifications.

Are you aware of compatibility problems with Windows 10 Pro version 2004? And solutions?
Thanks.