Logstash example -> Kibana. Field data loading is forbidden on [timestamp]

Hi,

Kibana 4.5.0
Logstash 2.4.0
ES 2.3.1
java 1.8.0_101

I'm following the logstash example documentation, using the sample input and the COMBINEDAPACHELOG filter.

This works as expected, the log is consumed and I can see the docs in ES. However, when I create an index pattern in Kibana, it only gives me the @timestamp field in the dropdown of time field names, so I select it for the index pattern. When I try to view the index pattern docs in Kibana->Discover, and I get error
Field data loading is forbidden on [timestamp]

So, what do I need to do to view these example logstash docs in Kibana? I assumed if I followed the documentation example it would be fine.

thanks

OK, so I upgraded to Kibana 4.6.1, and ES to 2.4.0 and now the issue does not occur.