According to your log the issue is actually not issuing a fan command but rather issuing a home command (G28). Your printer then seems to try to execute that and finally gives up because something (which it doesn't further clarify) goes wrong spectacularly and so bad it decides to enter kill state.
Make sure the printer is powered on, that the axes can move freely, that the end stops aren't engaged but DO engage when the head hits them, and that in general your printer is mechanically sound. If that fails, look into the firmware. In general, try printing from your printer's SD card or something like this, make sure THAT works, then try adding OctoPrint to the mix. This is your printer saying something is terribly wrong, not OctoPrint.