I browsed to this URL
http://opennms.lebanon.cd-adapco.com:8980/opennms/report/database/reportList.htm

and clicked on the "Execute Instantly" button.
in the Surveillance category field, I replace "%" with the name of one of my surveillance categories - "A-Jenkins" and let everything else at defaults:
Report Time Range: 7
Report Start Date: 2014-03-031
Report Format: PDF option selected

And clicked the "Run Report" button.

Next screen, without any delay, was the "The OpenNMS Web User Interface Has Experienced an Error" screen.

System Details
-------------- OpenNMS Version: 1.12.5
Java Version: 1.7.0_51 Oracle Corporation
Java Virtual Machine: 24.51-b03 Oracle Corporation
Operating System: Linux 2.6.32-431.5.1.el6.x86_64 amd64
Servlet Container: jetty/7.6.12.v20130726 (Servlet Spec 2.5)
User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/33.0.1750.152 Chrome/33.0.1750.152 Safari/537.36

Request Details
--------------- Locale: en_US
Method: POST
Path Info: null
Path Info (translated): null
Protocol: HTTP/1.1
URI: /opennms/errors/unknownexception.jsp
URL: http://opennms.lebanon.cd-adapco.com:8980/opennms/errors/unknownexception.jsp
Scheme: http
Server Name: opennms.lebanon.cd-adapco.com
Server Port: 8980

Exception Stack Trace
--------------------- net.sf.jasperreports.engine.fill.JRExpressionEvalException
at net.sf.jasperreports.engine.fill.JREvaluator.evaluate(JREvaluator.java:195)
at net.sf.jasperreports.engine.fill.JRCalculator.evaluate(JRCalculator.java:589)
at net.sf.jasperreports.engine.fill.JRCalculator.evaluate(JRCalculator.java:557)
at net.sf.jasperreports.engine.fill.JRFillSubreport.getParameterValues(JRFillSubreport.java:553)
at net.sf.jasperreports.engine.fill.JRFillSubreport.getParameterValues(JRFillSubreport.java:460)
at net.sf.jasperreports.engine.fill.JRFillSubreport.evaluateParameterValues(JRFillSubreport.java:359)
at net.sf.jasperreports.engine.fill.JRFillSubreport.evaluateSubreport(JRFillSubreport.java:339)
at net.sf.jasperreports.engine.fill.JRFillSubreport.evaluate(JRFillSubreport.java:263)
at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:258)
at net.sf.jasperreports.engine.fill.JRFillBand.evaluate(JRFillBand.java:499)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:2033)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:760)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:270)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:946)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:845)
at net.sf.jasperreports.engine.fill.JRFillSubreport.fillSubreport(JRFillSubreport.java:609)
at net.sf.jasperreports.engine.fill.JRSubreportRunnable.run(JRSubreportRunnable.java:59)
at net.sf.jasperreports.engine.fill.JRThreadSubreportRunner.run(JRThreadSubreportRunner.java:205)
at java.lang.Thread.run(Thread.java:744)