The libraries com.typesafe.akka:akka-actor_2.11:2.3.3 and com.typesafe:config:1.2.1 from the Forge maven repositories return a 404 every time.
Tried URLs: http://files.minecraftforge.net/maven/com/typesafe/akka/akka-actor_2.11/2.3.3/akka-actor_2.11-2.3.3.jar
http://files.minecraftforge.net/maven/com/typesafe/config/1.2.1/config-1.2.1.jar
Forge version.json in this particular instance was 1.10.2-forge1.10.2-12.18.3.2316 if that matters at all