Watch list NullPointer exception in getDocument

Error number 4001 in 4: Error while parsing velocity page xwiki:XWiki.WatchListMessage
Wrapped Exception: Failed to evaluate content with id [xwiki:XWiki.WatchListMessage]
com.xpn.xwiki.XWikiException: Error number 4001 in 4: Error while parsing velocity page xwiki:XWiki.WatchListMessage
Wrapped Exception: Failed to evaluate content with id [xwiki:XWiki.WatchListMessage]
at com.xpn.xwiki.render.XWikiVelocityRenderer.evaluate(XWikiVelocityRenderer.java:122)
at com.xpn.xwiki.plugin.mailsender.MailSenderPlugin.sendMailFromTemplate(MailSenderPlugin.java:806)
at com.xpn.xwiki.plugin.watchlist.WatchListNotifier.sendEmailNotification(WatchListNotifier.java:133)
at com.xpn.xwiki.plugin.watchlist.WatchListJob.executeJob(WatchListJob.java:262)
at com.xpn.xwiki.plugin.scheduler.AbstractJob.execute(AbstractJob.java:75)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)


Wrapped Exception:

org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getDocument' in  class com.xpn.xwiki.api.XWiki threw exception java.lang.NullPointerException at xwiki:XWiki.WatchListMessage[line 74, column 31]
at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:337)
at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:284)
at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:252)