Subject: The drone won't lift off after i updated to the latest firmware

I assume that you have followed the directions and power cycled the unit.  If so try two things.  Copy the hidden txt file, MISC/Log/xxxx.txt and post it here.  Format your SD card in FAT32 and download a new copy of the firmware to your computer.  Do a clean install of the unzipped bin file.  Insert the SD card into the gimbal and restart the upgrade process.  If one of the escs did not get upgraded this should take care of that.  Once you have upgraded, power cycle the unit, turn off your device then repower it.  Power the Tx, then the device and then the unit.  See if that helps.  If not I would remove the App, cycle the device and reinstall.