Unable to list all reviews of a project - Your request was unable to be processed

This is with Crucible. In the projects view there is a tab "reviews", that should list all reviews of the project. If i click on it I get an error page saying:

Your request was unable to be processed
javax.servlet.ServletException - javax.servlet.jsp.JspException: javax.el.ELException: java.lang.NullPointerException

javax.servlet.jsp.JspException: javax.el.ELException: java.lang.NullPointerException
javax.el.ELException: java.lang.NullPointerException
java.lang.NullPointerException

You are running release CR3.9.1 (20150910131426 2015-09-10), please report your release number when reporting bugs.

In the Fisheye log there is an explosion with lines like this:
2015-10-06 08:41:41,698 ERROR - Exception "javax.servlet.jsp.JspException: javax.el.ELException: java.lang.NullPointerException" (javax.servlet.ServletException) while processing "/WEB-INF/jsp/crucible/project/project.jsp" (Referer:"null")
javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.el.ELException: java.lang.NullPointerException
at org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:944)
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:879)
at org.apache.jsp.WEB_002dINF.jsp.crucible.project.project_jsp._jspService(project_jsp.java:137)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
...
2015-10-06 08:41:41,815 ERROR - Exception "javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.el.ELException: java.lang.NullPointerException" (javax.servlet.ServletException) while processing "/cru/browse/MYPROJ" (Referer:"null")
javax.servlet.ServletException: javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.el.ELException: java.lang.NullPointerException
at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:285)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:669)