DOCSP-9860: document resume token failure (#11)

* DOCSP-9860: document resume token failure

Author: Chris Cho

source/kafka-source.txt

@@ -32,7 +32,7 @@ Change Stream Event Document Format
 -----------------------------------
 
 A change stream event document contains several fields that describe the
-change:
+event:
 
 * The top-level ``_id`` field is used as the :manual:`resume token
   </changeStreams/#change-stream-resume>` which is
@@ -303,3 +303,16 @@ events, and broadcast changes after any collection data is updated.
 
    database=example
    copy.existing=true
+
+How to Recover from An Invalid Resume Token
+-------------------------------------------
+
+If the event your Connector pauses or shuts down long enough for the Change Stream resume token
+to expire from the :manual:`MongoDB Oplog </core/replica-set-oplog/>`_, you may encounter an error
+that prevents you from starting up the Connector. If you encounter this
+condition, you must delete the topic data referenced by
+the ``offset.storage.topic`` setting if you are using Distributed Mode or the
+file referenced by the ``offset.storage.file.filename`` setting (e.g.
+``/tmp/connect.offsets``) if you are using the Standalone mode. After you
+delete the appropriate data, you should be able to start your Connector
+workers and listen to the change stream.