Kali Boot Vesamenu.32 not found error.

Ive been trying to make a live usb of kali for about a week now. I've used dd commands on both mac and linux; followed every step on the install page on kali. I know the usb works cause I used it to install ubuntu on an old computer last week and boots if i put ubuntu back on it. But with kali i always get the message; Failed to load com32 file vesamenu.32. Every site says either change the config file or to put vesamenu onto the root. I've tried to do it by dragging it into the root and terminal comands but every time I've tried it says its read only. Can anybody help me with this? I'd love to start using kali!