I have changed from a terrific flying Hexcopter to a Quad, and now trying to get back to Hex. All firmware uploads have gone perfectly until trying to go back to Hex. I cannot get the firmware to load into the APM. After a long wait, the green loading indicator stops at approx. 3/4 and freezes. Eventually it times out and shows the following error message…COMPORT 4 does not exist . IT DOES EXIST AND SHOWS AS WORKING PROPERLY.
What is interesting is, I can CONNECT to the APM to verify the calibration modes, etc using the assigned COM4 ARDUINO MEGA 2560.
Everything worked fine on prior uploads, but now it suddenly does not work for firmware uploads.