This is a hotfix release intended to fix a single issue, which only manifests if a ZuluSCSI V6.4 is attached to a computer running ZuluSCSI-V6-util, and no SD card is physically present. The ZuluSCSI V6.4 will blink the LED five times, and while doing so, we were inadvertently USB HID connectivity.
End users must use the .uf2 file to update firmware. ZuluSCSI V6 boards are NOT updated via DFU, and attempting to update firmware via dfu-util will not work.
In order to enter UF2 mode, you need to attach your ZuluSCSI V6.4 to a computer via USB, and then press the RST/reset button twice. Then, just copy over the new UF2 file. Once the copy completes, the board will re-set itself, and be running the new firmware.