Failed to retrieve provision template (for client server)

Issue

Satellite 6.1.5 server: satserver.example.com
Capsule server: capsule.example.com

We are trying to kickstart a client server, we get a DHCP ip, tftp and subsequent kernel, but upon retrieving the Provisioning template for client server (client-server.example.com.com), we get the following error as seen in the foreman-proxy log:

 [2016-01-06T18:59:09.033073 #4561] ERROR -- : Failed to retrieve provision template for {"token"=>"b67b23ca-61b8-413d-b61d-967362f14b78", "splat"=>[], "captures"=>["provision"], "kind"=>"provision"}: Error retrieving provision for {"token"=>"b67b23ca-61b8-413d-b61d-967362f14b78", :url=>"http://client-server.example.com:8000"} from satserver.example.com: Net::HTTPInternalServerError
192.168.227.216 - - [06/Jan/2016 18:59:09] "GET /unattended/provision?token=b67b23ca-61b8-413d-b61d-967362f14b78 HTTP/1.1" 500 345 0.4196