Q: Doesn't Recognize Windows 10 as a valid install option.  Asks for Windows 7 or greater.

Use Windows 10 on your Mac with Boot Camp - Apple Support

I'm having the same issue, except is says "Windows 8 or later", instead of "Windows 7 or later". The Apple guide provided doesn't help me the slightest. I have the early 2015 MacBook Pro Retina 13" with all updates installed and downloaded the Windows 10 64-bit ISO from Microsoft website. I have tried multiple USB's, but I still get the same error message...

The signatures on Windows 10 ISOs are too new for BCA 5.1.4. My suggestion is to install W7/W8.1 and then upgrade to W10.

OK I found a solution that worked for me:

You have to have access to a Windows PC:

1. Download the Windows 10 media creation tool
2. Select "Create installation media for another PC"
3. Choose 64-bit architecture
4. Save as ISO on the USB
5. Once download and checking is complete, plug the USB into the Mac
6. Drag the Windows.iso to desktop
7. Start Boot Camp and select the Windows.iso
8. The installation should now finally continue!