I have been following the [Spring Security Reference](http://docs.spring.io/spring-security/site/docs/3.2.5.RELEASE/reference/htmlsingle/) and i added only this classes:

```
@Configuration
@EnableWebMvcSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http
        .authorizeRequests()
            .anyRequest().authenticated()
            .and()
        .formLogin().loginPage("/login")
        .permitAll()
            .and()
        .logout()
        .permitAll();
    }

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth
            .inMemoryAuthentication()
                .withUser("user").password("password").roles("USER").and()
                .withUser("user").password("password").roles("USER", "ADMIN");
    }
}

```

and

```
public class SecurityInitializer extends AbstractSecurityWebApplicationInitializer {

}

```

but when i run the server, an exception is thrown, i don't know what i am doing wrong, can you help me please?

This is the stacktrace:

```
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'springSecurityFilterChain' defined in class path resource [org/springframework/security/config/annotation/web/configuration/WebSecurityConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.servlet.Filter]: Factory method 'springSecurityFilterChain' threw exception; nested exception is java.lang.IllegalArgumentException: [Assertion failed] - this expression must be true
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:602)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1113)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1008)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:505)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:229)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:762)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:663)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:629)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:677)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:548)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:489)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
at javax.servlet.GenericServlet.init(GenericServlet.java:241)
at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:440)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:263)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1272)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:489)
at org.gradle.api.plugins.jetty.internal.JettyPluginWebAppContext.doStart(JettyPluginWebAppContext.java:112)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:224)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.gradle.api.plugins.jetty.internal.Jetty6PluginServer.start(Jetty6PluginServer.java:111)
at org.gradle.api.plugins.jetty.AbstractJettyRunTask.startJettyInternal(AbstractJettyRunTask.java:238)
at org.gradle.api.plugins.jetty.AbstractJettyRunTask.startJetty(AbstractJettyRunTask.java:191)
at org.gradle.api.plugins.jetty.AbstractJettyRunTask.start(AbstractJettyRunTask.java:162)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:63)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.doExecute(AnnotationProcessingTaskFactory.java:218)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:211)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:200)
at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:579)
at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:562)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:305)
at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.executeTask(AbstractTaskPlanExecutor.java:79)
at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:63)
at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:51)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:23)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:88)
at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:29)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:68)
at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:55)
at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:149)
at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106)
at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:86)
at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:80)
at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:33)
at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:24)
at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:36)
at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:26)
at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:51)
at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:171)
at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:237)
at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:210)
at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:35)
at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:206)
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169)
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
at org.gradle.launcher.Main.doAction(Main.java:33)
at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54)
at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35)
at org.gradle.launcher.GradleMain.main(GradleMain.java:23)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.servlet.Filter]: Factory method 'springSecurityFilterChain' threw exception; nested exception is java.lang.IllegalArgumentException: [Assertion failed] - this expression must be true
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:591)
... 102 more
Caused by: java.lang.IllegalArgumentException: [Assertion failed] - this expression must be true
at org.springframework.util.Assert.isTrue(Assert.java:65)
at org.springframework.util.Assert.isTrue(Assert.java:77)
at org.springframework.security.provisioning.InMemoryUserDetailsManager.createUser(InMemoryUserDetailsManager.java:59)
at org.springframework.security.config.annotation.authentication.configurers.provisioning.UserDetailsManagerConfigurer.initUserDetailsService(UserDetailsManagerConfigurer.java:61)
at org.springframework.security.config.annotation.authentication.configurers.userdetails.UserDetailsServiceConfigurer.configure(UserDetailsServiceConfigurer.java:48)
at org.springframework.security.config.annotation.authentication.configurers.userdetails.UserDetailsServiceConfigurer.configure(UserDetailsServiceConfigurer.java:33)
at org.springframework.security.config.annotation.AbstractConfiguredSecurityBuilder.configure(AbstractConfiguredSecurityBuilder.java:376)
at org.springframework.security.config.annotation.AbstractConfiguredSecurityBuilder.doBuild(AbstractConfiguredSecurityBuilder.java:325)
at org.springframework.security.config.annotation.AbstractSecurityBuilder.build(AbstractSecurityBuilder.java:39)
at org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration.getAuthenticationManager(AuthenticationConfiguration.java:78)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter.authenticationManager(WebSecurityConfigurerAdapter.java:236)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter.getHttp(WebSecurityConfigurerAdapter.java:178)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter.init(WebSecurityConfigurerAdapter.java:283)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter.init(WebSecurityConfigurerAdapter.java:68)
at org.munaycoop.taskmanager.security.WebSecurityConfig$$EnhancerBySpringCGLIB$$4b88c0dc.init(<generated>)
at org.springframework.security.config.annotation.AbstractConfiguredSecurityBuilder.init(AbstractConfiguredSecurityBuilder.java:367)
at org.springframework.security.config.annotation.AbstractConfiguredSecurityBuilder.doBuild(AbstractConfiguredSecurityBuilder.java:320)
at org.springframework.security.config.annotation.AbstractSecurityBuilder.build(AbstractSecurityBuilder.java:39)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration.springSecurityFilterChain(WebSecurityConfiguration.java:92)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration$$EnhancerBySpringCGLIB$$40bdb18f.CGLIB$springSecurityFilterChain$4(<generated>)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration$$EnhancerBySpringCGLIB$$40bdb18f$$FastClassBySpringCGLIB$$80796866.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:312)
at org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration$$EnhancerBySpringCGLIB$$40bdb18f.springSecurityFilterChain(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
... 103 more

```