Error rendering this wiki help message

While moving an issue, I clicked the help button on Step 3 of 4. The popup came up with the following error:

An error occurred whilst rendering this message. Please contact the administrators, and inform them of this bug. Details: ------- java.lang.NullPointerException at org.apache.velocity.context.InternalContextAdapterImpl.get(InternalContextAdapterImpl.java:162) at org.apache.velocity.runtime.parser.node.ASTReference.getVariableValue(ASTReference.java:623) at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:151) at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:220) 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 org.apache.velocity.app.VelocityEngine.mergeTemplate(VelocityEngine.java:419) at com.atlassian.velocity.DefaultVelocityManager.getEncodedBody(DefaultVelocityManager.java:74) at com.atlassian.jira.plugin.webwork.JiraPluginWebworkVelocityServlet.service(JiraPluginWebworkVelocityServlet.java:50) at javax.servlet.http.HttpServlet.service(HttpServlet.java:336) at com.evermind._hb.doFilter(.:59) at com.atlassian.jira.web.filters.AccessLogFilter.doFilter(AccessLogFilter.java:51) at com.evermind._ha.doFilter(.:16) at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:83) at com.evermind._ha.doFilter(.:20) at com.atlassian.seraph.filter.LoginFilter.doFilter(LoginFilter.java:91) at com.evermind._ha.doFilter(.:20) at com.atlassian.jira.web.filters.ActionCleanupDelayFilter.doFilter(ActionCleanupDelayFilter.java:29) at com.evermind._ha.doFilter(.:20) at com.atlassian.core.filters.AbstractEncodingFilter.doFilter(AbstractEncodingFilter.java:37) at com.evermind._cub._pod(.:383) at com.evermind._cub._bmc(.:177) at com.evermind._cub.forward(.:147) at com.atlassian.jira.web.dispatcher.JiraServletDispatcher.service(JiraServletDispatcher.java:248) at javax.servlet.http.HttpServlet.service(HttpServlet.java:336) at com.evermind._hb.doFilter(.:59) at com.atlassian.jira.web.filters.AccessLogFilter.doFilter(AccessLogFilter.java:51) at com.evermind._ha.doFilter(.:16) at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:119) at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:55) at com.atlassian.jira.web.filters.SitemeshExcludePathFilter.doFilter(SitemeshExcludePathFilter.java:38) at com.evermind._ha.doFilter(.:20) at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:182) at com.evermind._ha.doFilter(.:20) at com.atlassian.seraph.filter.LoginFilter.doFilter(LoginFilter.java:177) at com.evermind._ha.doFilter(.:20) at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:132) at com.atlassian.jira.web.filters.ProfilingAndErrorFilter.doFilter(ProfilingAndErrorFilter.java:25) at com.evermind._ha.doFilter(.:20) at com.atlassian.jira.web.filters.ActionCleanupDelayFilter.doFilter(ActionCleanupDelayFilter.java:37) at com.evermind._ha.doFilter(.:20) at com.atlassian.johnson.filters.JohnsonFilter.doFilter(JohnsonFilter.java:91) at com.evermind._ha.doFilter(.:20) at com.atlassian.jira.web.filters.gzip.GzipFilter.doFilter(GzipFilter.java:72) at com.evermind._ha.doFilter(.:20) at com.atlassian.core.filters.AbstractEncodingFilter.doFilter(AbstractEncodingFilter.java:37) at com.evermind._cub._pod(.:383) at com.evermind._cub._bmc(.:177) at com.evermind._ax._ltc(.:666) at com.evermind._ax._uab(.:191) at com.evermind._bf.run(.:62)