MOD-WIFI-ESP8266-DEV: Re-flashing of default firmware

[xpresso++]

Hi,

I have flashed a MOD-WIFI-ESP8266-DEV module with the nodeMCU and would like to go back to the default (AT-command) firmware.

Tried the Firmware Updater on https://www.olimex.com/Products/IoT/MOD-WIFI-ESP8266-DEV/open-source-hardware, but FLASH_DOWNLOAD_TOOL.exe crashes with "invalid image". Have also tried with different .bin from Espressif, flashing to different starting addresses, with no success.

Any advice?