I tried to set greenhopper license on dev.jira.com and got this exception:

2009-02-02 22:28:46.743943500 2009-02-02 22:28:46,740 TP-Processor7 [webwork.dispatcher.ServletDispatcher] Could not execute action
2009-02-02 22:28:46.743946500 java.lang.IllegalArgumentException: Action 'GreenHopper' not found or could not be initialized: Class not found
2009-02-02 22:28:46.743947500 at com.atlassian.jira.config.webwork.JiraActionFactory$JiraPluginActionFactory.getActionImpl(JiraActionFactory.java:60)
2009-02-02 22:28:46.743949500 at webwork.action.factory.ScriptActionFactoryProxy.getActionImpl(ScriptActionFactoryProxy.java:54)
2009-02-02 22:28:46.743977500 at webwork.action.factory.XMLActionFactoryProxy.getActionImpl(XMLActionFactoryProxy.java:54)
2009-02-02 22:28:46.743979500 at webwork.action.factory.PrefixActionFactoryProxy.getActionImpl(PrefixActionFactoryProxy.java:102)
2009-02-02 22:28:46.743980500 at webwork.action.factory.JspActionFactoryProxy.getActionImpl(JspActionFactoryProxy.java:53)
2009-02-02 22:28:46.743981500 at webwork.action.factory.CommandActionFactoryProxy.getActionImpl(CommandActionFactoryProxy.java:62)
2009-02-02 22:28:46.743990500 at webwork.action.factory.AliasingActionFactoryProxy.getActionImpl(AliasingActionFactoryProxy.java:96)
2009-02-02 22:28:46.743991500 at webwork.action.factory.CommandActionFactoryProxy.getActionImpl(CommandActionFactoryProxy.java:62)
2009-02-02 22:28:46.744004500 at webwork.action.factory.ContextActionFactoryProxy.getActionImpl(ContextActionFactoryProxy.java:36)
2009-02-02 22:28:46.744005500 at webwork.action.factory.PrepareActionFactoryProxy.getActionImpl(PrepareActionFactoryProxy.java:37)
2009-02-02 22:28:46.744007500 at webwork.action.factory.ParametersActionFactoryProxy.getActionImpl(ParametersActionFactoryProxy.java:46)
2009-02-02 22:28:46.744015500 at webwork.action.factory.ChainingActionFactoryProxy.getActionImpl(ChainingActionFactoryProxy.java:52)
2009-02-02 22:28:46.744016500 at webwork.action.factory.DefaultActionFactory.getActionImpl(DefaultActionFactory.java:125)
2009-02-02 22:28:46.744018500 at webwork.action.factory.ActionFactory.getAction(ActionFactory.java:63)
2009-02-02 22:28:46.744019500 at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:120)
2009-02-02 22:28:46.744063500 at com.atlassian.jira.web.dispatcher.JiraServletDispatcher.service(JiraServletDispatcher.java:178)
2009-02-02 22:28:46.744065500 at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
2009-02-02 22:28:46.744066500 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
2009-02-02 22:28:46.744067500 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
2009-02-02 22:28:46.744080500 at com.atlassian.jira.web.filters.AccessLogFilter.doFilter(AccessLogFilter.java:73)
2009-02-02 22:28:46.744082500 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
2009-02-02 22:28:46.744083500 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
2009-02-02 22:28:46.744084500 at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:119)
2009-02-02 22:28:46.744092500 at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:55)
2009-02-02 22:28:46.744094500 at com.atlassian.jira.web.filters.SitemeshExcludePathFilter.doFilter(SitemeshExcludePathFilter.java:38)
2009-02-02 22:28:46.744095500 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
2009-02-02 22:28:46.744096500 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)