I am trying to access Global Tool Configurations so I can change Maven settings and JDK settings. However, clicking the link from Manage Jenkins leads me to an Oops! page with the following stack trace: 

java.lang.AssertionError: InstanceIdentity is missing its singletonat org.jenkinsci.main.modules.instance_identity.InstanceIdentity.get(InstanceIdentity.java:133)at org.jenkinsci.main.modules.instance_identity.InstanceIdentityRSAProvider.getKeyPair(InstanceIdentityRSAProvider.java:23)at jenkins.model.identity.InstanceIdentityProvider$KeyTypes.get(InstanceIdentityProvider.java:161)at jenkins.model.identity.InstanceIdentityProvider$KeyTypes.getKeyPair(InstanceIdentityProvider.java:210)at jenkins.model.identity.IdentityRootAction.getUrlName(IdentityRootAction.java:42)at jenkins.model.Jenkins.getDynamic(Jenkins.java:3642)at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:638)at org.kohsuke.stapler.Function$MethodFunction.invoke(Function.java:343)at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:184)at org.kohsuke.stapler.MetaClass$10.dispatch(MetaClass.java:372)at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:715)Caused: javax.servlet.ServletExceptionat org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:765)at org.kohsuke.stapler.Stapler.invoke(Stapler.java:845)at org.kohsuke.stapler.Stapler.invoke(Stapler.java:649)at org.kohsuke.stapler.Stapler.service(Stapler.java:238)at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:841)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:135)at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:138)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:86)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at jenkins.security.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:117)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at jenkins.security.BasicHeaderProcessor.doFilter(BasicHeaderProcessor.java:92)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:90)at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:171)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:82)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1637)at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:190)at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1155)at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)at org.eclipse.jetty.server.Server.handle(Server.java:564)at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:317)at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110)at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:128)at org.eclipse.jetty.util.thread.Invocable$InvocableExecutor.invoke(Invocable.java:222)at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:294)at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:199)at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)at java.base/java.lang.Thread.run(Thread.java:844)