We moved this app to Cloudbees since CF is no longer free.
Examples were fixed in the wiki and in the source, but we haven’t released since.
https://github.com/excilys/gatling/blob/master/gatling-bundle/src/universal/user-files/simulations/basic/BasicExampleSimulation.scala#L14
Please use http://excilysbank.gatling.cloudbees.net instead.