ESP8266 Community Forum

Maybe you had interruption in your power or com connections and it started reboot during upload.
I would thus guess that then maybe because you have error in your init.lua which runs on boot it re boots.

I am in same position, continuous boot loop, bricked I guess, but for different reason
I was trying to use the GPIO's and wrote test script thus

file.remove("init.lua")
file.open("init.lua","w")
file.writeline([[pin = 12]])
file.writeline([[gpio.mode(pin,gpio.OUTPUT)]])
file.writeline([[gpio.write(pin,gpio.LOW)]])
file.close()

It tuns out that causes a reset.
There is no break or time between boots to send command to remove the init file using ESPLorer.
Best order a few ......
I must say this is still a fantastic bit of kit.
From boot takes about 3 seconds to retrieve a web page, that is including time to connect to wi-fi
No computer or mobile phone I know can do that, that fast!

You can reflash the firmware when you get in this state to erase the file system and recover the module.

If the text file contains characters not understood by the interpreter strange things happen(invalid register state), this is usually a result of copy and paste as this can take "hidden" formatting and paste it into a script.

As in the previous post ground GPIO_0 and re-flash a firmware file from a github and any module can be "un-bricked".