Atlassian Plugin Repository keeps loading and never finishes

Caused by: javax.servlet.ServletException: java.lang.NullPointerException
	at uk.ltd.getaheadplugin.dwr.DWRServlet.getContainer(DWRServlet.java:84)
	at uk.ltd.getaheadplugin.dwr.AbstractDWRServlet.init(AbstractDWRServlet.java:94)
	at com.atlassian.plugin.servlet.DelegatingPluginServlet.init(DelegatingPluginServlet.java:56)
	at com.atlassian.plugin.servlet.DefaultServletModuleManager$LazyLoadedServletReference.create(DefaultServletModuleManager.java:391)
	at com.atlassian.plugin.servlet.DefaultServletModuleManager$LazyLoadedServletReference.create(DefaultServletModuleManager.java:376)
	at com.atlassian.plugin.servlet.util.LazyLoadedReference$1.call(LazyLoadedReference.java:62)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at com.atlassian.plugin.servlet.util.LazyLoadedReference.get(LazyLoadedReference.java:74)
	... 112 more
Caused by: java.lang.NullPointerException
	at org.apache.felix.framework.FelixResolverState.getResolvedCandidates(FelixResolverState.java:649)
	at org.apache.felix.framework.Felix$FelixResolver.getResolvedCandidates(Felix.java:3977)
	at org.apache.felix.framework.ModuleImpl.diagnoseClassLoadError(ModuleImpl.java:2163)
	at org.apache.felix.framework.ModuleImpl.access$400(ModuleImpl.java:60)
	at org.apache.felix.framework.ModuleImpl$ModuleClassLoader.loadClass(ModuleImpl.java:1663)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:169)
	at uk.ltd.getaheadplugin.dwr.impl.DefaultContainer.addParameter(DefaultContainer.java:66)
	at uk.ltd.getaheadplugin.dwr.DWRServlet.getContainer(DWRServlet.java:60)
	... 120 more