PWM 5015 when clicking "Go Back" on confirm responses page

[Google Code Exporter]

What steps will reproduce the problem?
1. Select questions and enter responses
2. Click Save Responses
3. Click Go Back on confirmation page

What is the expected output? What do you see instead?
Expect to go back to the setup responses page, instead we get this error:

Unexpected error. If this error occurs repeatedly please contact your helpdesk. 
{ 5015 ERROR_UNKNOWN (An exception occurred processing JSP page 
/WEB-INF/jsp/setupresponses-confirm.jsp at line 44 41: <%@ include 
file="fragment/message.jsp" %> 42:
43: <% 44: for (final Challenge loopChallenge : 
responseBean.getResponseData().getResponseMap().keySet()) { 45: final String 
responseText = 
responseBean.getResponseData().getResponseMap().get(loopChallenge); 46: %> 47:
<%= StringEscapeUtils.escapeHtml(loopChallenge.getChallengeText()) %> 
Stacktrace:) } 

What version of PWM are you using?
PWM 1.7.1
Tomcat 7.0.57
JDK 7 update 71
Windows 2012 R2

What ldap directory and version are you using?
eDirectory 8.8 SP7

Please paste any error log messages below:

Original issue reported on code.google.com by [e-mail] on 30 Jan 2015 at 6:56