ArduPlane 3.7 Firmware Upgrade Mission Planner Not Working

Howdy, I am trying to upgrade from 3.6 to 3.7 in Mission Planner. When I select ArduPlane Stable (I assume this is 3.7) and then I get these errors: "Failed to download new frimware : System.Net.WebException: The operaton has timed out at System.Net.HttpWebRequest.GetResponse() at Mission Planner… "

My Pixhawk is detected (px4v2).

If I choose “PIck Previous Firmware” and select v3.6 it works as normal. So my connections are good. Is there something up with ver 3.7 from within Mission Planner?? Sort of lost on this and I really don’t want to learn how to build the firmwarm myself.

Can someone point me to the proper firmware that I can download and install using “Load Custom Firmware”.

Just found the firmware on ArduPilot, but which PX4 firmware: v1 or v2 or v4??

Thanks! Peter

I am guessing v2 since your board was detected by Mission Planner as px4v2. But I have honestly now idea what the different versions are.