Gatling Test in Blazemeter creates ClassNotFoundException - gatling

Question

I used the Taurus Gatling guide to create a simple performance test and uploaded the yaml and scala file to blazemeter. When i start the test in blazemeter there is no test result and the bzt.log contains a ClassNotFoundException.
The validator for the yaml says its fine and i can't find anything so I'm lost...
My blazemleter.yaml:
execution:
- executor: gatling
scenario: products
iterations: 15
concurrency: 3
ramp-up: 2
scenarios:
products:
script: productSimulation.scala
simulation: test.productSimulation
My productSimulation.scala is mostly copied from their documentation:
package test
import io.gatling.core.Predef._
import io.gatling.http.Predef._
class productSimulation extends Simulation {
// parse load profile from Taurus
val t_iterations = Integer.getInteger("iterations", 100).toInt
val t_concurrency = Integer.getInteger("concurrency", 10).toInt
val t_rampUp = Integer.getInteger("ramp-up", 1).toInt
val t_holdFor = Integer.getInteger("hold-for", 60).toInt
val t_throughput = Integer.getInteger("throughput", 100).toInt
val httpConf = http.baseURL("https://mydomain/")
val header = Map(
"Content-Type" -> """application/x-www-form-urlencoded""")
val sessionHeaders = Map("Authorization" -> "Bearer ${access_token}",
"Content-Type" -> "application/json")
// 'forever' means each thread will execute scenario until
// duration limit is reached
val loopScenario = scenario("products").forever() {
// auth
exec(http("POST OAuth Req")
.post("https://oauth-provider")
.formParam("client_secret", "...")
.formParam("client_id", "...")
.formParam("grant_type", "client_credentials")
.headers(header)
.check(status.is(200))
.check(jsonPath("$.access_token").exists
.saveAs("access_token")))
// read products
.exec(http("products")
.get("/products")
.queryParam("limit", 200)
.headers(sessionHeaders))
}
val execution = loopScenario
.inject(rampUsers(concurrency) over rampUp) // during for gatling 3.x
.protocols(httpConf)
setUp(execution).maxDuration(rampUp + holdFor)
}

Answer 1

After learning that i can execute the scala file as a test directly if i click the file directly and not the yaml i got better exceptions.
Basicly i made two mistakes:
my variables are named t_concurrency, ... while the execution definition uses a different name. ups.
since gatling 3.x the keyword for the inject is during, so the correct code is: rampUsers(t_concurrency) during t_rampUp
Now everything works.