Moderator: Mmiscool
Where I buy my ESP8266 boards from... (Banggood)
Found the solution here:
viewtopic.php?f=13&t=16507&start=4
It's the SPI flash P25Q80H, there is a patch for available for Arduino. So I applied the patch and compiled a new version, looks like this time it's working without issues.
I attached the .bin file, it's for ESP-01 boards with that P25Q80H 1MB (8 MBit) Flash.
To upload it, start the Basic Flasher Tool and then replace the file in ../build/1M. Use the same name as the old file. The .bin files will be replaced each time you start the tool again.