Bootcamp error.

Hey there,

Yesterday i tried installing windows with bootcamp which i have done before.

However it gives an error "your portable USB drive could not be created".

After searching the internet it kept popping up the same answer: Unmount the .iso file and restart the bootcamp process.

Which i did but it doesn't work because my bootcamp automatically mounts the .iso file the moment it starts its bootcamp process.

Any ideas or suggestions on how i can fix this?