Cant upload firmware

Iv tried everything I can think of and still it says no connection and firmware won’t upload. It will connect to MP though.

Did you ever find a fix? I’m having issues as well.

When I try to upload firmware to the APM 2.6 this is displayed in the “output”

Started downloading firmware.diydrones.com/Copter/st … Copter.hex
Finished downloading /var/folders/_5/952nff5s6bx6m63l7d5bjn0c0000gn/T/qt_temp.HcR329
Opening firmware file…
Hex file loaded: 239414 bytes
Unable to gain access to bootloader

The “Unable to gain access to bootloader” displays as a pop up message.