Exception when adding new mainContent

On a double page, added a new maincontent object, clicked on ok, the window did not close as if I had clicked on the + , entered a new title for the main content and clicked on OK. Got the following exception :

2008-07-23 11:44:57,507: ERROR [org.jahia.bin.JahiaAction] - Error
org.jahia.exceptions.JahiaException: User message=Field -1 cannot be found in mainContentList_rightcol, System message=JahiaContainer : Field -1 cannot be fo
in mainContentList_rightcol
at org.jahia.data.containers.JahiaContainer.getField(JahiaContainer.java:531)
at org.jahia.data.fields.FieldsEditHelperAbstract.processLastFields(FieldsEditHelperAbstract.java:207)
at org.jahia.engines.addcontainer.AddContainer_Engine.processLastScreen(AddContainer_Engine.java:392)
at org.jahia.engines.addcontainer.AddContainer_Engine.handleActions(AddContainer_Engine.java:281)
at org.jahia.operations.valves.EngineValve.processEngineRequest(EngineValve.java:180)
at org.jahia.operations.valves.EngineValve.invoke(EngineValve.java:82)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.J2ProcessActionValve.invoke(J2ProcessActionValve.java:144)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.SkeletonAggregatorValve.invoke(SkeletonAggregatorValve.java:73)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.PageAccessCheckValve.invoke(PageAccessCheckValve.java:73)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.OperationModeCheckValve.invoke(OperationModeCheckValve.java:83)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.SiteCheckValve.invoke(SiteCheckValve.java:78)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.EsiFragmentCacheReadValve.invoke(EsiFragmentCacheReadValve.java:329)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.operations.valves.EsiUrlCookieCheckValve.invoke(EsiUrlCookieCheckValve.java:313)
at org.jahia.pipelines.impl.GenericPipeline.invokeNext(GenericPipeline.java:208)
at org.jahia.pipelines.impl.GenericPipeline.invoke(GenericPipeline.java:195)
at org.jahia.operations.OperationManager.handleOperations(OperationManager.java:100)
at org.jahia.bin.JahiaAction.execute(JahiaAction.java:76)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:226)
at org.jahia.bin.JahiaRequestProcessor.process(JahiaRequestProcessor.java:82)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
at org.jahia.bin.Jahia.process(Jahia.java:1638)
at org.jahia.bin.Jahia.service(Jahia.java:841)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.jahia.bin.filters.esi.ESIFilter.doFilter(ESIFilter.java:110)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:619)
2008-07-23 11:44:57,741: INFO [org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/jahia]] - Your Jahia Server has generated an error. Please re
w the details below for additional information:
Severity : CRITICAL
Error : User message=Field -1 cannot be found in mainContentList_rightcol, System message=JahiaContainer : Field -1 cannot be found in mainContentList_rightc
URL : http://localhost:8080/jahia/Jahia/engineName/addcontainer/site/demo/op/edit/home/about_us/pid/6 Method : POST
Remote host : 127.0.0.1 Remote Address : 127.0.0.1
Request headers :
host:localhost:8080
user-agent:Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1
accept:text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8
accept-language:fr-ch,en-us;q=0.7,en;q=0.3
accept-encoding:gzip,deflate
accept-charset:ISO-8859-1,utf-8;q=0.7,*;q=0.7
keep-alive:300
connection:keep-alive
referer:http://localhost:8080/jahia/Jahia/engineName/addcontainer/site/demo/op/edit/home/about_us/pid/6?mode=display&clistid=54&cdefid=90&cpid=6&cparentid
cookie:jahiaWizardKey=cm9vdDpyb290cm9vdA%3D%3D; JSESSIONID=4A9AC442FA7B1E3C9E0E5523A30A118A; Jesi_Template_Username=root
content-type:application/x-www-form-urlencoded
content-length:284
Stack trace :
Cause level : 0 (level 0 is the most precise exception)