NullPointerException when editing guest account settings

Hi,

we installed TeamCity Docker Container and get the following error while editing the settings of the guest account.
Any ideas what could cause the NullPointerException?

ERROR - jetbrains.buildServer.SERVER - Error java.lang.NullPointerException while processing request: POST '/admin/editUser.html?userId=-1000&userId=-1000&username1=guest&name=Guest%20user&email=&publicKey=00a4c20eea0e5039012bf12b195329adc03e9bdfb0fde6e5bdab3a420cb7d3aaac4b46acacca9655c7642727508c28df90cb2b7d0f65a62e430840380b5c5b3c06b3d8f786278afbf17c4f8472b0a135a96f490734166996cfebf97d38bf124ecef93e36ec3d9992ea3dc5349d6df8c9fa78e1ebbc224e196bb9602dfdd75d55d3&administrator=true&_administrator=&tc-csrf-token=6e59cf1d-c6f7-4beb-aded-c0297e0822fb&submitUpdateUser=storeInDatabase&tab=userGroups&encryptedPassword1=&encryptedRetypedPassword=', from client 10.10.102.67:56587, authenticated as 'txs' (txs) {id=1}
java.lang.NullPointerException
 at jetbrains.buildServer.controllers.profile.AbstractUpdateUserController.doPost(AbstractUpdateUserController.java:44)
 at jetbrains.buildServer.controllers.BaseFormXmlController$1.handleRequest(BaseFormXmlController.java:54)
 at jetbrains.buildServer.controllers.AjaxRequestProcessor.processRequest(AjaxRequestProcessor.java:47)
 at jetbrains.buildServer.controllers.BaseFormXmlController.doHandle(BaseFormXmlController.java:52)
 at jetbrains.buildServer.controllers.BaseController.handleRequestInternal(BaseController.java:75)
 at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:147)
 at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:50)
 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:961)
 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:895)
 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
 at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:869)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
 at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
 at jetbrains.buildServer.maintenance.TeamCityDispatcherServlet.processedByMainServlet(TeamCityDispatcherServlet.java:42)
 at jetbrains.buildServer.maintenance.TeamCityDispatcherServlet.service(TeamCityDispatcherServlet.java:28)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
 at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
 at jetbrains.buildServer.web.jsp.JspPrecompilerFilter.doFilter(JspPrecompilerFilter.java:6)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
 at jetbrains.buildServer.web.DisableSessionIdFromUrlFilter.doFilter(DisableSessionIdFromUrlFilter.java:9)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
 at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:107)
 at jetbrains.buildServer.diagnostic.web.DiagnosticFilter.doFilter(DiagnosticFilter.java:13)
 at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
 at jetbrains.buildServer.web.DependencyParametersCalculationContextFilter.doFilter(DependencyParametersCalculationContextFilter.java:8)
 at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
 at jetbrains.buildServer.web.ContentSecurityPolicyFilter.doFilter(ContentSecurityPolicyFilter.java:10)
 at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
 at jetbrains.buildServer.web.CSRFFilter.doFilter(CSRFFilter.java:100)
 at org.springframework.web.filter.CompositeFilter$VirtualFilterChain.doFilter(CompositeFilter.java:112)
 at org.springframework.web.filter.CompositeFilter.doFilter(CompositeFilter.java:73)
 at jetbrains.buildServer.web.DelegatingFilter.doFilter(DelegatingFilter.java:37)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
 at jetbrains.buildServer.web.ResponseFragmentFilter.doFilter(ResponseFragmentFilter.java:1)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
 at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
 at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
 at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1770)
 at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1729)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
 at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
 at java.lang.Thread.run(Thread.java:748)