When the student user try to upload image through CKEditor following dialog appeared with an error message. 
当学生用户尝试通过CKEditor上传图像时，会出现以下对话框，并显示一条错误消息。
I have been searching for a solution for this.still unable to resolve. 我一直在寻找解决方案，仍然无法解决。
org.sakaiproject.exception.PermissionException user=58095d7f-9abf-405a-a746-b3bdd673f216 lock=content.new resource=/content/group/52b29c56-c607-4c31-966d-e0394a7eeb78/21761483_756386641230111_2474470716028905585_n.jpg at org.sakaiproject.content.impl.BaseContentService.unlock(BaseContentService.java:1784) at org.sakaiproject.content.impl.BaseContentService.addResource(BaseContentService.java:3587) at org.sakaiproject.content.impl.BaseContentService.addResource(BaseContentService.java:3141) at org.sakaiproject.content.impl.BaseContentService.addResource(BaseContentService.java:3211) at org.sakaiproject.content.impl.BaseContentService.addResource(BaseContentService.java:3200) at org.sakaiproject.connector.fck.FCKConnectorServlet.doPost(FCKConnectorServlet.java:355) at javax.servlet.http.HttpServlet.service(HttpServlet.java:646) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:30 org.sakaiproject.exception.PermissionException user = 58095d7f-9abf-405a-a746-b3bdd673f216 lock = content.new resource = / content / group / 52b29c56-c607-4c31-966d-e0394a7eeb78 / 21761483_756386641230111_2474470716028905585_n.jpg在orgsa上的项目。在org.sakaiproject.content.impl.BaseContentService.addResource（BaseContentService.java:3141）处的impl.BaseContentService.unlock（BaseContentService.java:1784）在org.sakaiproject.content.impl.BaseContentService.addResource（BaseContentService.java:3587）在org.sakaiproject.content.impl.BaseContentService.addResource（BaseContentService.java:3141）在org.sakaiproject.content.impl.BaseContentService.addResource（BaseContentService.java:3200）处org.sakaiproject.content.impl.BaseContentService.addResource（BaseContentService.java:3200）处org.sakaiproject.connector.fck.FCKConnectorServlet.doPost （FCKConnectorServlet.java:355），位于org.apache.catalina.core的javax.servlet.http.HttpServlet.service（HttpServlet.java:727），位于javax.servlet.http.HttpServlet.service（HttpServlet.java:646）。 ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:30 3) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:709) 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:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.serv 3）在org.sakaiproject.util.RequestFilter.doFilter（RequestFilter.java:709）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter的org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:208）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:208）（org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:220）处（ApplicationFilterChain.java:241）。 org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:501）上的catalina.core.StandardContextValve.invoke（StandardContextValve.java:122）org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java： 170）在org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:950）在org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:950）在org.apache.catalina.core.StandardEngineValve .invoke（StandardEngineValve.java:116）在org.apache.catalina.connector.CoyoteAdapter.serv ice(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1152) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:622) at java.lang.Thread.run(Thread.java:748) org.apache.coyote.http11上的ice（CoyoteAdapter.java:408），org.apache上org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:607）上的org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1041） .tomcat.util.net.JIoEndpoint $ SocketProcessor.run（JIoEndpoint.java:313）在java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1152）在java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor .java：622），位于java.lang.Thread.run（Thread.java:748）
