Interop.UIAutomationClient private/internal starting with version 10.0.0

@Domgrar, Welcome to Microsoft Q&A, based on my test, I almost reproduced your problem. And according to my research, there is no related doc to explain it. However, I find another way to use the code without any problems.

Please remove the reference Interop.UIAutomationClient.dll in your project and install the nuget-package Interop.UIAutomationClient.

After testing, I find the code will not generate that error(Tested in .NET Framework 4.8 console app):

Best Regards,

Jack

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That isn't what you want to do. That interop assembly was auto-generated from the corresponding COM type library when they created the project. It is simply a wrapper around the COM object just like you should be doing in your code. The version # is irrelevant here. It is v10 of the DLL because the apps that ship with the Win 10 SDK are v10. This has nothing to do with the version of the COM type library necessarily. If you're running Win 10 then you can (and should) generate this same interop assembly. When they imported the typelib they defined the namespace as UIAutomationClient and therefore that is where all the code went.

To do the same in your code remove any existing reference libraries for UI automation. Then add a COM reference to the UIAutomationClient library (which is currently v7 for Windows 10 it appears) and it'll add the necessary code that is equivalent to what this assembly has. You can go to your intermediate build directory to see the binary that was generated. Other than versioning it should be the same as what the SDK ships.