I lost the ability to use my 3dr telemetry in Mavericks when I updated my OS so I bought a windows 8.1 laptop. I heard it was the most stable for running mission planner. I went ahead and ran the wizard and setup my apm 2.6 board. Everything went well until I tried to setup my 3dr radio telemetry module. There wasn’t a com port listed in the pulldown for my 3dr radio so I installed the drivers recommended for windows on the APM website and restarted windows 8.1, as per directions. When I reopened mission planner, the additional com was available in the pulldown(in this case, com5). So I went to the 3dr settings page and selected com 5 @ 57600 baud and clicked on load settings. I got the error message "invalid com or in use"
any help you can provide would be greatly appreciated.
couple of notes-
running windows 8.1 64 bit version
3dr radio telemetry module 915 mhz