I’ve solved this “Invalid security token” error before with two methods.
This error usually happens because the security trust between the node and the server is broken or the encryption keys don’t match.
First, try deleting the host from the FOG Web UI, then perform a Quick Registration on the client machine and run the install again, this resets the trust relationship from scratch.
If the token.dat is still missing after that, open services.msc, manually start the FOGService, and reboot the computer. Manually triggering the service often forces the client to check in and finally generate the missing token.dat file.