Error erasing disk error number (-69888, 0) A error occurred erasing the disk. edwards-MacBook-Air:~ edward$

Hi,

I had the same issue until I used a 32GB USB stick.

With 8GB it didn't work...

This error will occur if the usb stick and the main drive have the same name.

Make sure you are not working from the volume you wish to make into the installer drive. CD to / or before you run the commands.