Another common error is when trying to copy the Windows installation files. Apple suggests that you move to macOS Mojave and try installing Windows 10 again, but the issue doesn't always go away. One of the errors is the 'Boot Camp installation failed' error. That being said, there are a lot of problems in using Bootcamp Assistant on latest macOS such as Mojave or High Serria. Part 1: Problems with Bootcamp Assistant on Mac
Part 1: Problems with Boot Camp Assistant App on Mac.