NullPointerException when commenting on an issue through edit screen

MethodInvocationException occurred getting message body from Velocity: java.lang.NullPointerException
java.lang.NullPointerException
	at com.atlassian.jira.util.JiraVelocityHelper.wasDeleted(JiraVelocityHelper.java:197)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:324)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:267)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:197)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
	at org.apache.velocity.runtime.parser.node.ASTReference.evaluate(ASTReference.java:307)
	at org.apache.velocity.runtime.parser.node.ASTExpression.evaluate(ASTExpression.java:45)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:68)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
	at org.apache.velocity.Template.merge(Template.java:256)
	at org.apache.velocity.app.VelocityEngine.mergeTemplate(VelocityEngine.java:450)
	at com.atlassian.velocity.DefaultVelocityManager.getEncodedBody(DefaultVelocityManager.java:76)
	at com.atlassian.velocity.DefaultVelocityManager.getEncodedBody(DefaultVelocityManager.java:60)
	at com.atlassian.jira.mail.MailingListCompiler.sendLists(MailingListCompiler.java:142)
	at com.atlassian.jira.mail.MailingListCompiler.sendLists(MailingListCompiler.java:84)
	at com.atlassian.jira.mail.IssueMailQueueItem.send(IssueMailQueueItem.java:114)
	at com.atlassian.mail.queue.MailQueueImpl.sendBuffer(MailQueueImpl.java:68)
	at com.atlassian.jira.service.services.mail.MailQueueService.run(MailQueueService.java:23)
	at com.atlassian.jira.service.JiraServiceContainer.run(JiraServiceContainer.java:59)
	at com.atlassian.jira.service.ServiceRunner.execute(ServiceRunner.java:50)
	at org.quartz.core.JobRunShell.run(JobRunShell.java:191)
	at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:516)