Latest beta ( build .21033) - unable to load custom firmware

Just tried to get latest master into my Orange Cube to no avail.
I have the correct set of drivers with MavLink+SLCAN UARTs and have gone thru all options: automatic, unplug and force bootloader.
24h ago it was working OK.

I check for MP beta upgrades daily, and it went thru one earlier today.

thanks for the report, fixing this now, new beta in 10 mins

I am also having this issue on 1.3.66, 1.3.68, and beta 1.3.7222.19663. Error is Unrecognized token at index1 (skipping call stack) at MissionPlanner.Utilities.Firmware.UploadPX4(). I have seen this from 3 different computers and from apj and hex files.

EDIT: Solved by reinstalling drivers and using the compiled apj file.