NullPointerException in the Web Management Console when undeploying a Processing Unit

[manager][1/19697] 2019-11-26 09:55:16,811 GSM INFO [com.gigaspaces.grid.gsm] - Processing Unit [hello-processor] monitor terminated
[webui][2/19683] 2019-11-26 09:55:17,505 WEBUI WARNING [org.eclipse.jetty.server.handler.ContextHandler.ROOT] - Exception while dispatching incoming RPC call; Caused by: com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.util.LinkedList com.gigaspaces.admin.webui.client.SpaceRuntimeInfoService.getSpaceTransactionsDetails(java.lang.String)' threw an unexpected exception: java.lang.NullPointerException
[webui][2/19683] at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
[webui][2/19683] at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
[webui][2/19683] at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
[webui][2/19683] at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
[webui][2/19683] at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
[webui][2/19683] at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
[webui][2/19683] at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHolder$NotAsyncServlet.service(ServletHolder.java:1401)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:760)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1617)
[webui][2/19683] at com.gigaspaces.admin.webui.server.filter.UserAgentFilter.doFilter(UserAgentFilter.java:60)
[webui][2/19683] at com.gigaspaces.admin.webui.server.filter.GzipFilter.doFilter(GzipFilter.java:117)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1604)
[webui][2/19683] at mvc.jetty.SmartFilter$SpringSecurity.doFilter(SmartFilter.java:125)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1596)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:545)
[webui][2/19683] at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
[webui][2/19683] at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:536)
[webui][2/19683] at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
[webui][2/19683] at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
[webui][2/19683] at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1592)
[webui][2/19683] at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
[webui][2/19683] at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1296)
[webui][2/19683] at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
[webui][2/19683] at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:485)
[webui][2/19683] at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1562)
[webui][2/19683] at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
[webui][2/19683] at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1211)
[webui][2/19683] at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
[webui][2/19683] at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
[webui][2/19683] at org.eclipse.jetty.server.Server.handle(Server.java:500)
[webui][2/19683] at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:386)
[webui][2/19683] at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:562)
[webui][2/19683] at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:378)
[webui][2/19683] at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:270)
[webui][2/19683] at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
[webui][2/19683] at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
[webui][2/19683] at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
[webui][2/19683] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
[webui][2/19683] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
[webui][2/19683] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
[webui][2/19683] at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
[webui][2/19683] at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:388)
[webui][2/19683] at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:806)
[webui][2/19683] at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:938)
[webui][2/19683] at java.lang.Thread.run(Thread.java:748)
[webui][2/19683] Caused by: java.lang.NullPointerException
[webui][2/19683] at com.gigaspaces.admin.webui.server.SpaceRuntimeInfoServiceImpl.getSpaceInstancesTransactionsDetails(SpaceRuntimeInfoServiceImpl.java:510)
[webui][2/19683] at com.gigaspaces.admin.webui.server.SpaceRuntimeInfoServiceImpl.getSpaceTransactionsDetails(SpaceRuntimeInfoServiceImpl.java:490)
[webui][2/19683] at sun.reflect.GeneratedMethodAccessor27.invoke(Unknown Source)