Thank you for the reply.
1) I am developing in Visual Studio 2017 in C-Sharp using OPC Studio 2024.1
2) Here is a very simple example of where the error occurs:
EasyDAClient client = new EasyDAClient();
// Error occurs on this READ call
object value = client.ReadItemValue("localhost","mahlo.10AOpcServer.1", "MyMachine.Current.KeyName");
This snippet is based on
THIS
demo code.
3) The exception is:
An OPC operation failure with error ID '{opcfoundation.org/DataAccess/}E_FAIL.0x800401F3' occurred, originating from '' and with depth of 1. The inner exception contains details about the problem.
The Inner Exception is:
Invalid class string\r\n+ This error usually means that the ProgID of the OPC Server you used is not registered on the specified computer.\r\n+ The machine name was 'localhost'. The server class used was 'mahlo.10AOpcServer.1'.\r\n+ Execution details: HasNativeClient=False, HasNetApiClient=True, ProcessBitness=32.\r\n+ The client method called (or event/callback invoked) was 'ReadMultipleItems[1]'."} System.Exception {OpcLabs.BaseLib.Runtime.InteropServices.ExtendedCOMException}
4) The IP address of the production equipment I am trying to access has not changed. I setup my
localhost version of the
mahlo 10A OPC-server on my new development computer with the same configuration as I had with the old development computer.
I was able to retrieve my old computer temporarily and I confirmed that this simple read demo works just fine. So I must have forgotten something when installing. Your help is greatly appreciated.