Avrdudess 24 Hot

A notorious issue in older GUIs was "silent verification failure" – the software said "OK," but the hex was corrupted. AVRDUDESS 24 Hot integrates a new verification engine that does a byte-by-byte CRC check after the standard AVRDUDE verification. If the chip is "hot" (i.e., just run) and has unstable clocking, the software warns you explicitly.

If you’re using an AVR at 24 MHz (requires external crystal/clock), programming via ISP can fail because the default SPI clock (1 MHz) may not be slow enough for the target to respond. avrdudess 24 hot

Solution: Version 24 "Hot" includes a Safety Check toggle. Uncheck it only if you know exactly what you are doing. Otherwise, the software will block writes that disable SPI (which would permanently block reprogramming). A notorious issue in older GUIs was "silent