>
>I'm not familiar with ARG, just some general suggestions:
>
>If ARG is implemented as an ActiveX or similar has it been properly registered? Perhaps try re-registering?
>

No, it's not. It's a VFP + DLL (not ActiveX).

>Is there a different antivirus program or any other unusual 3rd-party program running on the problem machine?

No, we isolated that.

>Is the user running with sufficient privileges?

That didn't make a difference when we tested it.

>Does it make any difference if you run your EXE in compatibility mode for an earlier version of Windows?

Good thought. I'll have them test it.

>Are there any other unusual entries in the System or Application event logs? Are all Win10 services that are set to auto-start, actually running?

Not really, but this is how we were able to track down the fact that it was something related to the group policy sync, which then lead us to the ARG DLL.