NPE when completing the user signup for a new user account in version 252. Stack
trace is below:

javax.servlet.ServletException: java.lang.NullPointerException
org.kohsuke.stapler.Stapler.invoke(Stapler.java:449)
org.kohsuke.stapler.MetaClass$7.doDispatch(MetaClass.java:230)
org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:440)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:361)
org.kohsuke.stapler.Stapler.service(Stapler.java:121)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:61)
hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:53)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:52)
hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:28)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:166)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:173)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:42)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:44)
hudson.security.HudsonFilter.doFilter(HudsonFilter.java:85)

root cause

java.lang.NullPointerException
hudson.security.HudsonPrivateSecurityRealm.createAccount(HudsonPrivateSecurityRealm.java:125)
hudson.security.HudsonPrivateSecurityRealm.doCreateAccount(HudsonPrivateSecurityRealm.java:86)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:103)
org.kohsuke.stapler.Function.bindAndinvoke(Function.java:57)
org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:75)
org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:440)
org.kohsuke.stapler.MetaClass$7.doDispatch(MetaClass.java:230)
org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:30)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:440)
org.kohsuke.stapler.Stapler.invoke(Stapler.java:361)
org.kohsuke.stapler.Stapler.service(Stapler.java:121)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:61)
hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:53)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:52)
hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:28)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:166)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:173)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:42)
hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:55)
hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:44)
hudson.security.HudsonFilter.doFilter(HudsonFilter.java:85)