I was able to flash this board but it felt random (aka when i sometimes unplugged or pushed flash button for a few seconds.
I'm on the newest OSX version all updates. Also I've tried switching from Stable to Staging and back (removing rebooting and changing the .json link)
I have Board selected as NodeMcu 1.0
speed 115200 though i've tried down to 9600
port is the correct one.
My friend on linux doesn't need to push flash buttons or anything
I stumbled on this post: http://www.esp8266.com/viewtopic.php?p=25718 but not sure if any fixes since