When trying to create issue via mail (both system email as well as dedicated project) I get exception:

io.onedev.commons.utils.ExplicitException: No issue creation setting (sender: me@domain.net, project: helpdesk)

When I go to helpdesk settings and click on [+] button to add new issue creation settings I get following error:

java.lang.NullPointerException
	at io.onedev.server.web.editable.milestonechoice.MilestoneMultiChoiceEditor.onInitialize(MilestoneMultiChoiceEditor.java:54)
	at org.apache.wicket.Component.fireInitialize(Component.java:878)
	at org.apache.wicket.MarkupContainer$3.component(MarkupContainer.java:1077)
	at org.apache.wicket.MarkupContainer$3.component(MarkupContainer.java:1073)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:144)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:162)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:123)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:192)
	at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:984)
	at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1072)
	at org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:1048)
	at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:242)
	at io.onedev.server.web.editable.issue.fieldsupply.FieldListEditPanel.onInitialize(FieldListEditPanel.java:213)
	at org.apache.wicket.Component.fireInitialize(Component.java:878)
	at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1071)
	at org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:1048)
	at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:242)
	at io.onedev.server.web.editable.BeanEditor$1.onInitialize(BeanEditor.java:165)
	at org.apache.wicket.Component.fireInitialize(Component.java:878)
	at org.apache.wicket.MarkupContainer$3.component(MarkupContainer.java:1077)
	at org.apache.wicket.MarkupContainer$3.component(MarkupContainer.java:1073)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:144)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:162)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:123)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:192)
	at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:984)
	at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1072)
	at org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:1048)
	at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:242)
	at io.onedev.server.web.editable.BeanEditor.onInitialize(BeanEditor.java:257)
	at org.apache.wicket.Component.fireInitialize(Component.java:878)
	at org.apache.wicket.MarkupContainer$3.component(MarkupContainer.java:1077)
	at org.apache.wicket.MarkupContainer$3.component(MarkupContainer.java:1073)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:144)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:123)
	at org.apache.wicket.util.visit.Visits.visitChildren(Visits.java:192)
	at org.apache.wicket.MarkupContainer.visitChildren(MarkupContainer.java:984)
	at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1072)
	at org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:1048)
	at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:242)
	at io.onedev.server.web.editable.servicedesk.IssueCreationSettingEditPanel.onInitialize(IssueCreationSettingEditPanel.java:104)
	at org.apache.wicket.Component.fireInitialize(Component.java:878)
	at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1071)
	at org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:1048)
	at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:242)
	at io.onedev.server.web.component.modal.ModalPanel.onBeforeRender(ModalPanel.java:46)
	at org.apache.wicket.Component.internalBeforeRender(Component.java:950)
	at org.apache.wicket.Component.beforeRender(Component.java:1018)
	at org.apache.wicket.Component.internalPrepareForRender(Component.java:2236)
	at org.apache.wicket.Component.prepareForRender(Component.java:2275)
	at org.apache.wicket.page.XmlPartialPageUpdate.writeComponent(XmlPartialPageUpdate.java:98)
	at org.apache.wicket.page.PartialPageUpdate.writeComponents(PartialPageUpdate.java:248)
	at org.apache.wicket.page.PartialPageUpdate.writeTo(PartialPageUpdate.java:161)
	at org.apache.wicket.ajax.AjaxRequestHandler.respond(AjaxRequestHandler.java:359)
	at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:917)
	at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
	at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:97)
	at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:274)
	at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:231)
	at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:302)
	at org.apache.wicket.protocol.ws.AbstractUpgradeFilter.processRequestCycle(AbstractUpgradeFilter.java:70)
	at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:203)
	at org.apache.wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:137)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at io.onedev.server.web.DefaultWicketServlet.service(DefaultWicketServlet.java:43)
	at io.onedev.server.web.DefaultWicketServlet$$EnhancerByGuice$$4c7ce51.CGLIB$service$0(<generated>)
	at io.onedev.server.web.DefaultWicketServlet$$EnhancerByGuice$$4c7ce51$$FastClassByGuice$$e35a994d.invoke(<generated>)
	at com.google.inject.internal.cglib.proxy.$MethodProxy.invokeSuper(MethodProxy.java:228)
	at com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:76)
	at io.onedev.server.persistence.SessionInterceptor$1.call(SessionInterceptor.java:23)
	at io.onedev.server.persistence.DefaultSessionManager.call(DefaultSessionManager.java:79)
	at io.onedev.server.persistence.SessionInterceptor.invoke(SessionInterceptor.java:18)
	at com.google.inject.internal.InterceptorStackCallback$InterceptedMethodInvocation.proceed(InterceptorStackCallback.java:78)
	at com.google.inject.internal.InterceptorStackCallback.intercept(InterceptorStackCallback.java:54)
	at io.onedev.server.web.DefaultWicketServlet$$EnhancerByGuice$$4c7ce51.service(<generated>)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
	at org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1626)
	at com.google.inject.servlet.DefaultFilterPipeline.dispatch(DefaultFilterPipeline.java:47)
	at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:133)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
	at io.onedev.server.git.GoGetFilter.doFilter(GoGetFilter.java:87)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
	at io.onedev.server.git.GitLfsFilter.doFilter(GitLfsFilter.java:440)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
	at io.onedev.server.git.GitFilter.doFilter(GitFilter.java:336)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:450)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
	at io.onedev.server.util.jetty.DisableTraceFilter.doFilter(DisableTraceFilter.java:28)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:548)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1434)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:501)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1349)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:763)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at org.eclipse.jetty.server.Server.handle(Server.java:516)
	at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:388)
	at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:633)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:380)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
	at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131)
	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:386)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
	at java.lang.Thread.run(Thread.java:750)