My WDS MDT PXE boot process was working fine until I installed the latest versions a couple of days ago of Windows 10 Deployment Kit and ADK WinPE for Windows 10. I've seen a possible fix (see below)
1.Open WDS
2.Right-click your server in the left pane and open properties.
3.Open tab “TFTP” and change the maximum block size to eg 1024.
4.Restart your WDS server.
The trouble is there is no TFTP tab in the properties of my WDS? Any ideas?