The error disappeared. But finally, I concluded that this GUI doesn't expose the button to UIAutomation. I don't know why it appears on "**%ProgramFiles(x86)%\\Windows Kits\\10\bin\\10.0.18362.0\\x86\\inspect.exe**". There might be any other ways to find it in C#. For this specific GUI, I will take legacy, coordinate based approach using twapi. ``` eagle { set bool(true) [object invoke -create System.Boolean Parse true] set prop(invoke) [object invoke AutomationElement IsInvokePatternAvailableProperty] set cond(invoke) [object create PropertyCondition $prop(invoke) $bool(true)] set elems(invoke) [$elem(elan) -alias FindAll Descendants $cond(invoke)] $elems(invoke) Count } # => 0 ``` Thank you very much for your advice. It will help me automate modern GUIs in future.