Cannot delete a project, stacktrace on error screen

java.lang.NullPointerException
	at com.atlassian.jira.security.roles.CachingProjectRoleAndActorStore$ProjectRoleActorsCache.removeByProject(CachingProjectRoleAndActorStore.java:213)
	at com.atlassian.jira.security.roles.CachingProjectRoleAndActorStore.removeAllRoleActorsByProject(CachingProjectRoleAndActorStore.java:137)
	at com.atlassian.jira.security.roles.DefaultProjectRoleManager.removeAllRoleActorsByProject(DefaultProjectRoleManager.java:200)
	at com.atlassian.jira.project.DefaultProjectManager.removeProject(DefaultProjectManager.java:238)
	at com.atlassian.jira.project.CachingProjectManager.removeProject(CachingProjectManager.java:290)
	at com.atlassian.jira.bc.project.DefaultProjectService.deleteProject(DefaultProjectService.java:650)
	at com.atlassian.jira.bc.project.DefaultProjectService.deleteProject(DefaultProjectService.java:577)
	at com.atlassian.jira.web.action.project.DeleteProject.doExecute(DeleteProject.java:64)
	at webwork.action.ActionSupport.execute(ActionSupport.java:165)
	at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:76)
	at webwork.interceptor.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:39)
	at webwork.interceptor.NestedInterceptorChain.proceed(NestedInterceptorChain.java:31)
	at webwork.interceptor.ChainedInterceptor.intercept(ChainedInterceptor.java:16)
	at webwork.interceptor.DefaultInterceptorChain.proceed(DefaultInterceptorChain.java:35)
	at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:205)
	at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:143)
	at com.atlassian.jira.web.dispatcher.JiraWebworkActionDispatcher.service(JiraWebworkActionDispatcher.java:152)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.jira.web.filters.steps.ChainedFilterStepRunner.doFilter(ChainedFilterStepRunner.java:74)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.core.filters.HeaderSanitisingFilter.doFilter(HeaderSanitisingFilter.java:44)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:46)
	at com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)
	at com.atlassian.applinks.core.rest.context.ContextFilter.doFilter(ContextFilter.java:25)
	at com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)
	at com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)
	at com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:77)
	at com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:63)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.jira.web.filters.accesslog.AccessLogFilter.executeRequest(AccessLogFilter.java:103)
	at com.atlassian.jira.web.filters.accesslog.AccessLogFilter.doFilter(AccessLogFilter.java:87)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.jira.security.xsrf.XsrfTokenAdditionRequestFilter.doFilter(XsrfTokenAdditionRequestFilter.java:54)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
	at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
	at com.atlassian.jira.web.filters.PathExclusionFilter.doFilter(PathExclusionFilter.java:118)
	at com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:46)
	at com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:77)
	at com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:63)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:211)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.security.auth.trustedapps.filter.TrustedApplicationsFilter.doFilter(TrustedApplicationsFilter.java:98)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.seraph.filter.BaseLoginFilter.doFilter(BaseLoginFilter.java:150)
	at com.atlassian.jira.web.filters.JiraLoginFilter.doFilter(JiraLoginFilter.java:70)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:46)
	at com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)
	at com.atlassian.oauth.serviceprovider.internal.servlet.OAuthFilter.doFilter(OAuthFilter.java:71)
	at com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)
	at com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)
	at com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:77)
	at com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:63)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:99)
	at com.atlassian.jira.web.filters.JIRAProfilingFilter.doFilter(JIRAProfilingFilte