Invalid PXE Server List Format

I am trying to get a client to boot from the PXE server. The client and the deployment (PXE) server are in 2 different subnets.

The client can reach the server and find the file, but I get the following error:

There is a DHCP server in the client subnet, which uses option 66 (next-server) to point to the PXE server, and option 67 is set to BStrap\x64\BStrap.0

I cannot seem to get past this error and I am unable to find a solution to my problem.