Java Exception while removing group "confluence-users"

Created 3 more users (besides admin), created 3-4 more groups, assigned each user to one of the new groups (leaving them in "confluence-users"), then tried to remove group "confluence-users" with specifying "None" for "Move to" field. Hit "Confirm" and got the following error page:

Cause:
java.lang.IllegalStateException: Cannot deactivate transaction synchronization - not active

Stack Trace: [hide]

java.lang.IllegalStateException: Cannot deactivate transaction synchronization - not active
at org.springframework.transaction.support.TransactionSynchronizationManager.clearSynchronization(TransactionSynchronizationManager.java:230)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.cleanupAfterCompletion(AbstractPlatformTransactionManager.java:507)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionManager.java:392)
at com.atlassian.confluence.util.XWorkTransactionInterceptor.onThrowable(XWorkTransactionInterceptor.java:201)
at com.atlassian.confluence.util.XWorkTransactionInterceptor.intercept(XWorkTransactionInterceptor.java:140)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163)
at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:34)
at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:163)
at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:115)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.serviceAction(ServletDispatcher.java:278)
at com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:248)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:145)
at com.atlassian.confluence.util.profiling.ProfilingPageFilter.parsePage(ProfilingPageFilter.java:146)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:61)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:165)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.LoginFilter.doFilter(LoginFilter.java:181)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.johnson.filters.JohnsonFilter.doFilter(JohnsonFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.springframework.orm.hibernate.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:117)
at bucket.custom.FlushingSpringSessionInViewFilter.doFilterInternal(FlushingSpringSessionInViewFilter.java:30)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:73)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:132)
at com.atlassian.confluence.util.error.ProfilingAndErrorFilter.doFilter(ProfilingAndErrorFilter.java:25)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.core.filters.AbstractEncodingFilter.doFilter(AbstractEncodingFilter.java:36)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2417)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:193)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:781)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:549)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:589)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:666)
at java.lang.Thread.run(Thread.java:536)

Referer URL: Unknown

Build Information:
Uptime: 20 hours, 45 minutes, 36 seconds
Version: 1.1.2
Build Number: 57

Server Information:
Application Server: Apache Tomcat/4.1.29
Servlet Version: 2.3
Database Dialect: net.sf.hibernate.dialect.HSQLDialect

Memory Information:
Total Memory: 126 MB
Free Memory: 72 MB
Used Memory: 54 MB

System Information:
System Date: Friday, 25 Jun 2004
System Time: 10:46:18
System Favourite Colour: Almond
Java Version: 1.4.1_02
Java Vendor: Sun Microsystems Inc.
JVM Version: 1.0
JVM Vendor: Sun Microsystems Inc.
JVM Implementation Version: 1.4.1_02-b06
Java Runtime: Java(TM) 2 Runtime Environment, Standard Edition
Java VM: Java HotSpot(TM) Server VM
User Name: Administrator
User Timezone: America/Los_Angeles
Operating System: Windows 2000 5.0
OS Architecture: x86

Request Information:
Request URL: http://localhost:8080/admin/users/doremovegroup.action

• Scheme: http
• Server: localhost
• Port: 8080
• URI: /500page.jsp
• - Context Path:
• - Servlet Path: /500page.jsp
• - Path Info: null
• - Query String: null
  Request Attributes:
• javax.servlet.error.servlet_name : action
• com.atlassian.confluence.setup.SpringSessionInViewFilter.sessionFactory : true
• webwork.valueStack : com.opensymphony.xwork.util.OgnlValueStack@a7abf8
• javax.servlet.error.exception : org.springframework.dao.CleanupFailureDataAccessException: Failed to flush session before close: could not delete: com.opensymphony.user.provider.hibernate.entity.HibernateGroup#1; nested exception is net.sf.hibernate.JDBCException: could not delete: com.opensymphony.user.provider.hibernate.entity.HibernateGroup#1
• javax.servlet.error.message :
• os_securityfilter_already_filtered : true
• atlassian.core.util.groups.cache.key : [confluence-users, confluence-administrators]
• com.atlassian.johnson.filters.JohnsonFilter_already_filtered : true
• loginfilter.already.filtered : true
• atlassian.core.seraph.original.url : /admin/users/doremovegroup.action
• javax.servlet.error.request_uri : /admin/users/doremovegroup.action
• javax.servlet.jsp.jspException : java.lang.IllegalStateException: Cannot deactivate transaction synchronization - not active
• javax.servlet.error.status_code : 500
• _sitemesh_filterapplied : true

Request Logging:
0 log statements generated by this request: