You mean this guy? It's still there it seems.
java.lang.NoSuchFieldException: refSet
at java.lang.Class.getDeclaredField(Class.java:1882)
at net.liftweb.http.PointlessActorToWorkAroundBug$$anonfun$act
$2$$anonfun$apply$2.apply(LiftServlet.scala:722)
at net.liftweb.http.PointlessActorToWorkAroundBug$$anonfun$act
$2$$anonfun$apply$2.apply(LiftServlet.scala:714)
at scala.actors.Reaction.run(Reaction.scala:78)
at net.liftweb.http.ActorSchedulerFixer$$anon$1$$anon$3.run
(LiftServlet.scala:673)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask
(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run
(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
java.lang.NullPointerException
at scala.runtime.BoxesRunTime.boxToInteger(Unknown Source)
at scala.actors.Actor$$anonfun$scala$actors$Actor$$seq$1.apply
(Actor.scala:800)
at scala.actors.Actor$$anonfun$scala$actors$Actor$$seq$1.apply
(Actor.scala:794)
at scala.actors.Reaction.run(Reaction.scala:82)
at net.liftweb.http.ActorSchedulerFixer$$anon$1$$anon$3.run
(LiftServlet.scala:673)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask
(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run
(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)