Boot Camp Assistant Install Fails to install Windows 10 1709. "An error occurred while copying the Windows installation files."
I created a macOS tool to solve the problem and create a new ISO that works. I also wrote up an explanation. It is related max file size of FAT32 and how Boot Camp Assistant prepares the installation.

https://twocanoes.com/using-larger-windows-10-isos-with-boot-camp-assistant/