Thank you for the provided responses. My best guess is that you have accidentally damaged your hardware during reflashing. From your description of the LED, the firmware is starting as it should, but the serial interface is not working. There could be many possible causes for that; for example, you may have accidentally damaged the connector. I can’t make any assumptions as to why your own boards are not working since I don’t have any information about them.
there is a missing file?
No. The error message is shown because the debugger has attempted to load the source code from the location specified in the ELF; that location is specific to the system where the ELF was built, i.e., my workstation. The error message should be ignored.
Why is your elf file 3 times bigger than mine?
I’ve compiled it in the debug mode.
I sent you yesterday an email, could we get in touch for a custom development?
Yes, I’m going to continue via email.