After compiling (no errors/warnings), firmware flash and reset, I received the following error message:
d��|��;snc��$��b�dc䌜���$��c�lsdl$��|��soc��d$l���b�c�ܜ��d��c��dsd�d��|��{rnc��l���#�c�Ĝ��㌄c�dc$sd��sl���bl�b;|�cld���lb��o��g��l�|�l�$��$������l`�'����c��b���cl�c�l{ls�n�����g����c{#��b���c�x��l{l��d�ioctl(1, 0)
ioctl(5, 0)
readblocks(0, 3ffeeb00(4096))
readblocks(0, 3ffee850(4096))
Traceback (most recent call last):
File "", line 9, in
File "", line 13, in check_bootsec
File "", line 14, in readblocks
OSError: 5
ioctl(1, 0)
ioctl(5, 0)
readblocks(0, 3ffef050(4096))
NLR jump failed

What I have overlooked or done wrong?
Hardware: ESP8266 (MCULua V3)

This is a great project . Thank you very much.

Many greetings from Christian Fey