Have you defined the network access account? I've seen that error at applying the OS phase because my NAC didn't have the correct privileges.
You have multiple issues going on so can you give some more info about your environment? You said it's a new 1702 install but what OS are you deploying? Is MDT integrated? Are you pxe booting or using media? Will F8 bring up the cmd window in winpe before you start the task sequence?