NPE When your plugin fails to load

[mjensenbitbucket-bot]

If you try and install an invalid plugin, you get a very unhelpful error message:

[error] ac - An error occurred checking the status of a plugin install
java.lang.NullPointerException: null
    at com.atlassian.connect.play.java.upm.UpmClient$InstallStatus.fromResponse(UpmClient.java:199) ~[ac-play-java_2.10-0.6.0.jar:0.6.0]
    at com.atlassian.connect.play.java.upm.UpmClient$4.apply(UpmClient.java:96) ~[ac-play-java_2.10-0.6.0.jar:0.6.0]
    at com.atlassian.connect.play.java.upm.UpmClient$4.apply(UpmClient.java:90) ~[ac-play-java_2.10-0.6.0.jar:0.6.0]
    at play.libs.F$Promise$PromiseActor.onReceive(F.java:425) ~[play_2.10-2.1.3.jar:2.1.3]
    at akka.actor.UntypedActor$$anonfun$receive$1.applyOrElse(UntypedActor.scala:159) ~[akka-actor_2.10-2.1.0.jar:na]
    at akka.actor.ActorCell.receiveMessage(ActorCell.scala:425) ~[akka-actor_2.10-2.1.0.jar:na]

(Checking the hidden logs of the application indicated an error in my descriptor.)