Memory corrupted after micropython firmware programming Arduino OPTA

[panther50500]

I'm using Arduino Opta with MicroPython and two of them work fine. However, I ordered one online and encountered a problem after programming the firmware. Files in file explorers (Linux or Windows) are corrupted (special characters displayed and undefined files created). If I try to program it with Arduino (with c language), it seems to work fine.
I returned it to the reseller who sent me another one but it has the same problem.
Someone else have this problem ?
Thanks
Frédéric

try with :

ARDUINO_OPTA-20241129-v1.24.1.dfu (which works with another boards)
ARDUINO_OPTA-20250326-v1.25.0-preview.410.gdd7a950bb.dfu (which works with at least one other board)

[panther50500]

README.txt

pybcdc.inf.txt

main.py.txt

boot.py.txt

i create extension .txt at boot.py, main.py and pybcdc.inf to add them

[sebromero]

Hi @panther50500 ! Thank you for sharing this issue. Unfortunately the functionality to transfer files to and from the board (also when reading/writing files) using the file explorer is not very stable. It's a MicroPython issue. We don't recommend doing that. Instead I recommend to either use mpremote or to use our own Editor which has file handling capabilities.

[panther50500]

Hi @sebromero, thank you for your return. I should have given you more details. In fact, I also tested this by unmounting the disk from File Explorer, using the Arduino Lab interface for MicroPython and Thonny.
In both cases, I was unable to copy or read the files; the copy was either impossible, or they were either not present or incorrect.
On Arduino Lab for micropython, it freezed :

or

[facchinm]

Cross referencing micropython/micropython#17020 for mainline support (not really IDE related, so I'd close it here)