Neo4j Traverser - Just get an item with specific type

Starting at any given Node I want to run the traverser till it hits a node which has "contentpage" as type (all nodes have a type-property).

I've tried it with the following traverser

{
    "order":"depth first",
    "uniqueness" : "node global",
    "relationships":[
        {"type":"CONTAINS","direction":"in"},
        {"type":"HAS","direction":"in"}
    ],
    "prune evaluator":{"language":"javascript","body":"position.endNode().getProperty('type')!='contentpage';"},
    "max depth":10000000
}

But all I get is a HTTP-Error 500. Any Ideas?

Edit: Here's a stack trace (I've trimmed it a bit because it was huge)

Problem accessing /db/data/node/782350/traverse/node. Reason:

    javax.script.ScriptException: sun.org.mozilla.javascript.WrappedException: Wrapped org.neo4j.graphdb.NotFoundException: type property not found for NodeImpl#782348. (<Unknown Source>#1) in <Unknown Source> at line number 1
Caused by:

org.neo4j.server.rest.domain.EvaluationException: javax.script.ScriptException: sun.org.mozilla.javascript.WrappedException: Wrapped org.neo4j.graphdb.NotFoundException: type property not found for NodeImpl#782348. (<Unknown Source>#1) in <Unknown Source> at line number 1
    at org.neo4j.server.rest.domain.EvaluatorFactory$CompiledScriptExecutor.eval(EvaluatorFactory.java:183)
    at org.neo4j.server.rest.domain.EvaluatorFactory$ScriptedPruneEvaluator.pruneAfter(EvaluatorFactory.java:241)
    at org.neo4j.kernel.impl.traversal.TraversalDescriptionImpl$WrappedPruneEvaluator.evaluate(TraversalDescriptionImpl.java:239)
    at org.neo4j.kernel.impl.traversal.MultiEvaluator.evaluate(MultiEvaluator.java:41)
    at org.neo4j.kernel.impl.traversal.TraversalBranchImpl.initialize(TraversalBranchImpl.java:93)
    at org.neo4j.kernel.impl.traversal.TraversalBranchImpl.next(TraversalBranchImpl.java:112)
    at org.neo4j.kernel.impl.traversal.StartNodeTraversalBranch.next(StartNodeTraversalBranch.java:50)
    at org.neo4j.kernel.PreorderDepthFirstSelector.next(PreorderDepthFirstSelector.java:48)
    at org.neo4j.kernel.impl.traversal.TraverserImpl$TraverserIterator.fetchNextOrNull(TraverserImpl.java:127)
    at org.neo4j.kernel.impl.traversal.TraverserImpl$TraverserIterator.fetchNextOr开发者_C百科Null(TraverserImpl.java:94)
    at org.neo4j.helpers.collection.PrefetchingIterator.hasNext(PrefetchingIterator.java:55)
    at org.neo4j.server.rest.web.DatabaseActions.traverse(DatabaseActions.java:922)
    at org.neo4j.server.rest.web.RestfulGraphDatabase.traverse(RestfulGraphDatabase.java:641)
    at sun.reflect.GeneratedMethodAccessor99.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)

To begin with, it seems you should have

 "uniqueness" : "node global"

Generally, you can't send in nulls. Just don't set something if you want the default. Have a look here for more information: Neo4j REST API.

Edit for updated question:

So the exception says:

NotFoundException: type property not found for NodeImpl

which is caused by:

position.endNode().getProperty('type')

To avoid this, set a default value for the the property, for example:

getProperty('type','')

Can you have a look at the data/log/*.log and data/messages.log file for possible stack-traces?

Thanks