I made an update with the wrong WLED file. I used "WLED_0.15.0-b4_ESP8266.bin". The good news are: i can connect to the WLED device. The bad news are: i could not update to "WLED_0.15.0-b4_ESP02.bin.gz". The message is always "Update failed! Please check your file and retry!"...
I also tried to downgrade, to configure LEDs and so on. But at this time, nothing works for me. Is there a chance to update to the correct WLED firmware?