Jenkins is failing to start - jenkins

Question

Jenkins installation that was previously running is no longer booting. When trying to access if via web, I get an HTTP 503 error due to the service being unavailable.
Jenkins 1.567-1.1
CentOS 6.7
java version "1.6.0_39"
OpenJDK Runtime Environment (IcedTea6 1.13.11) (rhel-1.13.11.0.el6_7-x86_64)
OpenJDK 64-Bit Server VM (build 23.25-b01, mixed mode)
I've tried installing several font packages, and have checked that it's running in headless mode. It is.
Here is the stack trace:
SEVERE: Failed to initialize Jenkins
hudson.util.AWTProblem: java.lang.NullPointerException
at hudson.WebAppMain.contextInitialized(WebAppMain.java:182)
at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:782)
at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:424)
at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:774)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:249)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1242)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:717)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:494)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:95)
at org.eclipse.jetty.server.Server.doStart(Server.java:282)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at winstone.Launcher.<init>(Launcher.java:154)
at winstone.Launcher.main(Launcher.java:354)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at Main._main(Main.java:293)
at Main.main(Main.java:98)
Caused by: java.lang.NullPointerException
at sun.font.FontManager.getDefaultPlatformFont(FontManager.java:3409)
at sun.java2d.SunGraphicsEnvironment$2.run(SunGraphicsEnvironment.java:263)
at java.security.AccessController.doPrivileged(Native Method)
at sun.java2d.SunGraphicsEnvironment.<init>(SunGraphicsEnvironment.java:164)
at sun.awt.X11GraphicsEnvironment.<init>(X11GraphicsEnvironment.java:254)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:534)
at java.lang.Class.newInstance(Class.java:379)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:82)
at sun.font.FontManager.initSGEnv(FontManager.java:1121)
at sun.font.FontManager.findFont2D(FontManager.java:1876)
at java.awt.Font.getFont2D(Font.java:477)
at java.awt.Font.getFamily(Font.java:1198)
at java.awt.Font.getFamily_NoClientCode(Font.java:1172)
at java.awt.Font.getFamily(Font.java:1164)
at java.awt.Font.toString(Font.java:1661)
at hudson.util.ChartUtil.<clinit>(ChartUtil.java:229)
at hudson.WebAppMain.contextInitialized(WebAppMain.java:181)
... 19 more
May 20, 2016 9:07:53 AM org.eclipse.jetty.util.log.JavaUtilLog warn
WARNING: Failed startup of context w.{,file:/var/cache/jenkins/war/},/var/cache/jenkins/war
java.lang.NullPointerException
at jenkins.util.groovy.GroovyHookScript.run(GroovyHookScript.java:63)
at hudson.util.BootFailure.publish(BootFailure.java:43)
at hudson.WebAppMain.contextInitialized(WebAppMain.java:244)
at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:782)
at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:424)
at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:774)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:249)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1242)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:717)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:494)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at org.eclipse.jetty.server.handler.HandlerWrapper.doStart(HandlerWrapper.java:95)
at org.eclipse.jetty.server.Server.doStart(Server.java:282)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:64)
at winstone.Launcher.<init>(Launcher.java:154)
at winstone.Launcher.main(Launcher.java:354)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at Main._main(Main.java:293)
at Main.main(Main.java:98)