com.typesafe.config.ConfigException$Missing: reference.conf: No configuration setting found for key ‘default’

I created a jar file of my Akka application. When I run the jar file by the command

java -jar file.jar

then I see this error. What could be possibly wrong and how can I fix this?

[ERROR] [04/28/2022 14:11:03.296] [main] [KnowledgePortalRest(akka://knowledge-portal-actor-system)] Error starting application:
com.typesafe.config.ConfigException$Missing: reference.conf @ jar:file:/home/knoldus/knolx-service/target/scala-2.12/sbt-1.0/knowledge-portal-rest-assembly-2.2.1.jar!/reference.conf: 13-1466: No configuration setting found for key 'default'
    at com.typesafe.config.impl.SimpleConfig.findKeyOrNull(SimpleConfig.java:156)
    at com.typesafe.config.impl.SimpleConfig.findOrNull(SimpleConfig.java:174)
    at com.typesafe.config.impl.SimpleConfig.find(SimpleConfig.java:188)
    at com.typesafe.config.impl.SimpleConfig.find(SimpleConfig.java:193)
    at com.typesafe.config.impl.SimpleConfig.getBoolean(SimpleConfig.java:218)
    at com.typesafe.sslconfig.util.ConfigLoader$.$anonfun$booleanLoader$2(Configuration.scala:186)
    at com.typesafe.sslconfig.util.ConfigLoader$.$anonfun$booleanLoader$2$adapted(Configuration.scala:186)
    at com.typesafe.sslconfig.util.ConfigLoader$$anon$2.load(Configuration.scala:173)
    at com.typesafe.sslconfig.util.EnrichedConfig.get(Configuration.scala:22)
    at com.typesafe.sslconfig.ssl.SSLConfigParser.parse(Config.scala:498)
    at com.typesafe.sslconfig.ssl.SSLConfigFactory$.parse(Config.scala:486)
    at com.typesafe.sslconfig.akka.AkkaSSLConfig$.defaultSSLConfigSettings(AkkaSSLConfig.scala:34)
    at com.typesafe.sslconfig.akka.AkkaSSLConfig$.createExtension(AkkaSSLConfig.scala:29)
    at com.typesafe.sslconfig.akka.AkkaSSLConfig$.createExtension(AkkaSSLConfig.scala:19)
    at akka.actor.ActorSystemImpl.registerExtension(ActorSystem.scala:1006)
    at akka.actor.ExtensionId.apply(Extension.scala:79)
    at akka.actor.ExtensionId.apply$(Extension.scala:78)
    at com.typesafe.sslconfig.akka.AkkaSSLConfig$.apply(AkkaSSLConfig.scala:24)
    at com.typesafe.sslconfig.akka.AkkaSSLConfig$.apply(AkkaSSLConfig.scala:19)
    at akka.http.scaladsl.HttpExt.<init>(Http.scala:82)
    at akka.http.scaladsl.Http$.createExtension(Http.scala:1132)
    at akka.http.scaladsl.Http$.createExtension(Http.scala:901)
    at akka.actor.ActorSystemImpl.registerExtension(ActorSystem.scala:1006)
    at akka.actor.ExtensionId.apply(Extension.scala:79)
    at akka.actor.ExtensionId.apply$(Extension.scala:78)
    at akka.http.scaladsl.Http$.apply(Http.scala:1127)
    at com.knoldus.HttpServer.start(HttpServer.scala:28)
    at com.knoldus.HttpServerApp$.delayedEndpoint$com$knoldus$HttpServerApp$1(HttpServerApp.scala:70)
    at com.knoldus.HttpServerApp$delayedInit$body.apply(HttpServerApp.scala:24)
    at scala.Function0.apply$mcV$sp(Function0.scala:39)
    at scala.Function0.apply$mcV$sp$(Function0.scala:39)
    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:17)
    at scala.App.$anonfun$main$1$adapted(App.scala:80)
    at scala.collection.immutable.List.foreach(List.scala:392)
    at scala.App.main(App.scala:80)
    at scala.App.main$(App.scala:78)
    at com.knoldus.HttpServerApp$.main(HttpServerApp.scala:24)
    at com.knoldus.HttpServerApp.main(HttpServerApp.scala)

Answer

This kind of error happens when the application is unable to found the reference.conf configuration file in the classpath.

Make sure such file is present in the jar you’ve built.