I doubt very much it is anything to do with BobCAD, I assume if you are on a modern computer running Win 10 then it is unlikely to have a Serial port on it so are you using a USB to Serial adapter? If so then it could possibly be that having updated to Win 10 the Drivers for the USB to Serial adapter need to be updated, try doing a search for the latest Drivers for Win 10 for the Adapter you are using. That would be the first place I would look after a Win 10 update from a previous OS, Win7 maybe ??
Stay Safe
Regards
Rob