Steps to reproduce:

  - create a workspace, a section and a document in the workspace
  - publish the document in the section using the publish tab
  - watch the logs:

14:57:30,685 ERROR [IndexingTask] failed to index document 'Candygram-1.0' with type 'File': org.nuxeo.ecm.core.api.WrappedException: Exception: java.lang.NullPointerException. message: null
org.nuxeo.ecm.core.search.api.client.IndexingException: org.nuxeo.ecm.core.api.WrappedException: Exception: java.lang.NullPointerException. message: null
        at org.nuxeo.ecm.core.search.backend.compass.CompassBackend.index(CompassBackend.java:326)
        at org.nuxeo.ecm.core.search.service.SearchServiceImpl.index(SearchServiceImpl.java:254)
        at org.nuxeo.ecm.core.search.service.SearchServiceImpl.index(SearchServiceImpl.java:265)
        at org.nuxeo.ecm.core.search.threading.IndexingTask.run(IndexingTask.java:72)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
        at java.lang.Thread.run(Thread.java:595)
Caused by: org.nuxeo.ecm.core.api.WrappedException: Exception: java.lang.NullPointerException. message: null
        at org.nuxeo.ecm.core.search.backend.compass.CompassBackend.index(CompassBackend.java:319)
        ... 6 more

The document appears to be indexed though ; maybe thamks to the asynchronous indexer.