Datastax studio cannot read schema for graph - datastax-enterprise

Question

I have a DSE 6 Cluster in production, everything works great.
Lately I wanted to plug the version 6 of datastax studio on it.
I configured the connection properly with ssl and authentication and the connection test is successful.
The problem is that DSE Studio doesn't seem to be able to get the schema from the server.
I'm using the last java version from Oracle, and I configured JCE with jce unlimited strength jurisdiction policy files for java 8.
I have this error in the studio log:
23:02:22.740 [Studio-akka.actor.default-dispatcher-12] ERROR
com.datastax.studio.client.SchemaManager ID: TS: - Unexpected exception getting cql schema for connection null: java.lang.NullPointerException
23:02:22.744 [Studio-akka.actor.default-dispatcher-42] WARN com.datastax.studio.streaming.websocket.CQLSchemaBroadcaster ID: TS: - Schema stream provider got null cql schema
23:02:22.740 [Studio-akka.actor.default-dispatcher-32] ERROR com.datastax.studio.application.EventuateEventBus ID: TS: - Unhandled exception during publishing (event=SparkSQLConnectionClosed(connectionId=null), listener=com.datastax.studio.client.SchemaManager$$Lambda$71/1502197135#4121ef79):
java.lang.NullPointerException: null
at java.util.concurrent.ConcurrentHashMap.replaceNode(ConcurrentHashMap.java:1106) ~[?:1.8.0_161]
at java.util.concurrent.ConcurrentHashMap.remove(ConcurrentHashMap.java:1097) ~[?:1.8.0_161]
at com.datastax.studio.client.SchemaManager.stopSparkSqlSchemaRefresh(SchemaManager.java:473) ~[classes/:?]
at com.datastax.studio.client.SchemaManager.lambda$init$5(SchemaManager.java:181) ~[classes/:?]
at com.datastax.studio.application.EventuateEventBus$EventListenerActor.lambda$new$0(EventuateEventBus.java:116) ~[classes/:?]
at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:26) [akka-actor_2.11-2.4.17.jar:?]
at akka.japi.pf.UnitCaseStatement.apply(CaseStatements.scala:21) [akka-actor_2.11-2.4.17.jar:?]
at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:123) [scala-library-2.11.8.jar:?]
at akka.japi.pf.UnitCaseStatement.applyOrElse(CaseStatements.scala:21) [akka-actor_2.11-2.4.17.jar:?]
at scala.PartialFunction$OrElse.apply(PartialFunction.scala:167) [scala-library-2.11.8.jar:?]
at com.rbmhtechnology.eventuate.EventsourcedView$class.receiveEvent(EventsourcedView.scala:227) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at com.rbmhtechnology.eventuate.AbstractEventsourcedActor.com$rbmhtechnology$eventuate$ConfirmedDelivery$$super$receiveEvent(AbstractEventsourcedActor.scala:32) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at com.rbmhtechnology.eventuate.ConfirmedDelivery$class.receiveEvent(ConfirmedDelivery.scala:83) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at com.rbmhtechnology.eventuate.AbstractEventsourcedActor.com$rbmhtechnology$eventuate$PersistOnEvent$$super$receiveEvent(AbstractEventsourcedActor.scala:32) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at com.rbmhtechnology.eventuate.PersistOnEvent$class.receiveEvent(PersistOnEvent.scala:79) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at com.rbmhtechnology.eventuate.AbstractEventsourcedActor.receiveEvent(AbstractEventsourcedActor.scala:32) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at com.rbmhtechnology.eventuate.EventsourcedView$$anonfun$initiated$1.applyOrElse(EventsourcedView.scala:457) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at akka.actor.Actor$class.aroundReceive(Actor.scala:497) [akka-actor_2.11-2.4.17.jar:?]
at com.rbmhtechnology.eventuate.AbstractEventsourcedView.aroundReceive(AbstractEventsourcedView.scala:55) [eventuate-core_2.11-0.8.1.jar:0.8.1]
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526) [akka-actor_2.11-2.4.17.jar:?]
at akka.actor.ActorCell.invoke(ActorCell.scala:495) [akka-actor_2.11-2.4.17.jar:?]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257) [akka-actor_2.11-2.4.17.jar:?]
at akka.dispatch.Mailbox.run(Mailbox.scala:224) [akka-actor_2.11-2.4.17.jar:?]
at akka.dispatch.Mailbox.exec(Mailbox.scala:234) [akka-actor_2.11-2.4.17.jar:?]
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) [scala-library-2.11.8.jar:?]
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) [scala-library-2.11.8.jar:?]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) [scala-library-2.11.8.jar:?]
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) [scala-library-2.11.8.jar:?]
On the server side there is nothing special in the logs.
Do you know what the problem could be?