I see.
Due to what you said, I tried now with v1.6.2...
It worked on the first time..
(and with QIO)
BTW,
I used the files in the 1024+1024 folder, and of course chose --flash_size 4MB-c1.
Technically I can also use the files in the 512+512 folder, and choose --flash_size 4MB without -C1.
I assume both would work,
so what would be better?