diff --git a/headless_client/worker_world.coffee b/headless_client/worker_world.coffee
index 667481858..1680b86aa 100644
--- a/headless_client/worker_world.coffee
+++ b/headless_client/worker_world.coffee
@@ -137,20 +137,18 @@ work = () ->
 
 
   self.onWorldError = onWorldError = (error) ->
-    self.postMessage type: "end-load-frames"
-    if error instanceof Aether.problems.UserCodeProblem
-      #console.log "Aether userCodeProblem occured."
-      unless self.postedErrors[error.key]
-        problem = error.serialize()
+    if error.isUserCodeProblem
+      errorKey = error.userInfo.key
+      if not errorKey or not self.postedErrors[errorKey]
         self.postMessage
           type: "user-code-problem"
-          problem: problem
-
-        self.postedErrors[error.key] = problem
+          problem: error
+        self.postedErrors[errorKey] = error
     else
       console.log "Non-UserCodeError:", error.toString() + "\n" + error.stack or error.stackTrace
-    self.cleanUp()
-
+      self.cleanUp()
+    return true
+    
   self.onWorldLoadProgress = onWorldLoadProgress = (progress) ->
     #console.log "Worker onWorldLoadProgress"
     self.postMessage
diff --git a/scripts/transpile.coffee b/scripts/transpile.coffee
index 5b4794b4c..2c60a1c91 100644
--- a/scripts/transpile.coffee
+++ b/scripts/transpile.coffee
@@ -13,19 +13,23 @@ Aether.addGlobal 'Vector', require '../app/lib/world/vector'
 Aether.addGlobal '_', _
 
 transpileLevelSession = (sessionID, cb) ->
-  query = LevelSession.findOne("_id": sessionID).select("submittedCode").lean()
+  query = LevelSession.findOne("_id": sessionID).select("submittedCode submittedCodeLanguage").lean()
   query.exec (err, session) ->
     if err then return cb err
     submittedCode = session.submittedCode
+    unless session.submittedCodeLanguage
+      throw "SUBMITTED CODE LANGUAGE DOESN'T EXIST"
+    else
+      console.log "Transpiling code for session #{session._id} in language #{session.submittedCodeLanguage}"
     transpiledCode = {}
-    console.log "Updating session #{sessionID}"
+    #console.log "Updating session #{sessionID}"
     for thang, spells of submittedCode
       transpiledCode[thang] = {}
       for spellID, spell of spells
 
         aetherOptions =
           problems: {}
-          language: "javascript"
+          language: session.submittedCodeLanguage 
           functionName: spellID
           functionParameters: []
           yieldConditionally: spellID is "plan"
@@ -41,7 +45,6 @@ transpileLevelSession = (sessionID, cb) ->
       "_id": sessionID
     update =
       "transpiledCode": transpiledCode
-      "submittedCodeLanguage": "javascript"
     query = LevelSession.update(conditions,update)
 
     query.exec (err, numUpdated) -> cb err