Microsoft cautions Mac owners to not clean install install Windows 10 Creators Update on Boot Camp. You need to install Windows 10 Anniversary Update (Build 1607), and then update via Windows Update.

Microsoft will not fix this until the next major Windows 10 release.

If you install the Creators Update ISO on a Mac clean, you will get an EFI boot error. Microsoft says the only fix is to use the Boot Camp Assistant to remove the entire partition, and start over.

To help with this, Microsoft will keep the Anniversary Update ISOs and MCT online. Just choose it from the Select Edition menu on this page. Notably, the Creators Update ISOs are now live, so you can also update to Creators Update now too.

In this specific case, I am not sure yet if you can run the Media Creation Tool / ISO to do an (offline) upgrade in-place an Anniversary Update. But I suspect you can as the .efi files are already put into place. Windows 10 in-place upgrades don’t tend to touch the EFI bootloader files, which is partly why it’s so low-risk to completely rewrite the whole operating system.

Source: Microsoft