@priis You constantly use the wrong firmware images with the wrong tools. Stop panicking. If you have a WiPy3, then you have to use the Pycom tools. The pycom firmware will be downloaded by the pycom update tool on the fly. You do not have to download the firmware beforehand. The firmware updating tool is here: https://pycom.io/downloads/ The instructions are in the link I gave you earlier: https://docs.pycom.io/gettingstarted/installation/firmwaretool Please follow the instructions. You do not have to use esptool.py of firmware images from other sources.