I'm using version 188.8.131.52, windows 10 remote, windows 7 host. The program I'm running on host is Media Shout (Church presentation software). None of the drop-down menus work, i.e. clicking on the down arrow does not produce the menu picks.
Please try enabling the Capture alpha-blending windows feature. To enable it, in the main Viewer window, right-click on the remote connection in the address book and select Properties. Navigate to the Additional Properties tab and tick the Capture alpha-blending windows checkbox: