"You must set the ES_CLASSPATH var"

Hello. I've got ES running locally just fine. I'm trying to get it running on a server now, however, and I'm stymied by "You must set the ES_CLASSPATH var" when trying to start elasticsearch. I'm currently using 5.0, but other versions have the same issue. Using OpenJDK 1.8.0_101-b13. Any ideas on how to get this up and running?

See my answer here