Hello Chulmin Yang,
Thank you for confirming that ReactiveUI.WPF is not causing the issues with recording.
You can check the WPF test configurations
and ensure that the correct path, for the application under test, is set. Alternatively, you should be able to attach the recorder to a running instance of the WPF application
and record the test steps.
As you have mentioned, it might be a permissions issue, as Test Studio requires administrator permissions to ensure that the recording and execution are not restricted. Try using the admin account on the machine with Test Studio and see if that makes a difference.
Please do not hesitate to contact us again.