"FDL2 failed" is never a problem with your code. It is always a problem with the hardware stack below it. Treat it as a physical layer issue, not a software bug. Check your cables, check your drivers, and for the love of debugging, buy an FTDI cable with a ferrite bead.
Use compressed air or a toothpick to ensure there is no lint in the device's charging port. 2. Reinstall Drivers fdl2 failed
: A message like "FDL2: incompatible partition" indicates a mismatch that may require a full repartition within the tool's settings to proceed. Fdl2 Failed [exclusive] "FDL2 failed" is never a problem with your code