Error 97 on ActiveX Property/Invoke Node in LabVIEW

Issue Details

I am trying to communicate with an ActiveX server application using LabVIEW. However, when I pass the automation refnum to any property node or Invoke node I get error 97. The error message can look like the one in the image below:
Why are the property and invoke nodes not accepting this refnum and how to solve this error?

Solution

This error is usually caused by an invalid reference of the ActiveX class that the property or invoke node is trying to access. Please follow these troubleshooting steps in order to fix the issue:

• A possible cause for this error is not passing the automation refnum to the Automation Open VI node before passing it to the property or invoke nodes. Make sure to include the "Automation Open" node as shown in the following image.

• The issue can be caused by corruption in the third-party software or because it is missing in the development computer. Because of this the ActiveX class that the Automation Open VI is trying to create may throw an error and output an invalid refnum. Use the highlight execution option or a probe to see if there is an error code being thrown when creating the instance of the automation refnum. If there is additional information about the error, contact the third-party software technical support for additional advice or try reinstalling the third-party driver by following the software provider's instructions.