• Operating System: Windows 10 1709
• Python Version: 3.6 x64
• Sonoff model: S20 EU

Please also drag and drop the generated debug_########.log file onto the issue so it is attached.
debug_1512295526.log

When trying to use SonOTA to flash a "freshly" unboxed S20, it seems that the unit does not want to boot from FinalStage (minimal) firmware image to the regular firmware.

After replugging the device, the FinalStage SSID appears again, thus indicating that the regular firmware was not flashed after it was downloaded from the server (see log).

I had the same issue with another unit yesterday, this one I was able to flash with the UART like normal afterwards (even though I half-destroyed it with crappy screwdrivers in the progress 👎 ; note to self: invest in quality equipment).

Hoping that we can fix this one with debug collected using the script, or collected over IP. I can ping the 192.168.4.1 IP when connected to the FinalStage SSID (although I'm not sure which services are exposed over IP). Otherwise it might take me some time to follow up, as I want to keep this one physically more intact.