OAF getting error when click download file howerver once come back using back broswer button able to

<!--StartFragment--> oracle.apps.fnd.framework.OAException: oracle.jbo.InvalidObjNameException: JBO-25005: Object name 1 for type Variable is invalidat oracle.apps.fnd.framework.webui.OAPageErrorHandler.prepareException(OAPageErrorHandler.java:1358)at oracle.apps.fnd.framework.webui.OAPageErrorHandler.processErrors(OAPageErrorHandler.java:1545)at oracle.apps.fnd.framework.webui.OAPageBean.processFormRequest(OAPageBean.java:3739)at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:2194)at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:596)at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:487)at _pages.__oa._jspService(__oa.java:233)at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:301)at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.apps.fnd.security.csrf.GuardFilter.doFilter(GuardFilter.java:275)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.apps.fnd.security.WLFilter.doFilter(WLFilter.java:162)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.apps.jtf.cabo.interceptor.JTFWrapperFilter.doFilter(JTFWrapperFilter.java:151)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.apps.jtf.base.session.ReleaseResFilter.doFilter(Unknown Source)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.apps.fnd.security.AppsServletFilter.doFilter(AppsServletFilter.java:504)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.security.jps.ee.http.JpsAbsFilter$1.run(JpsAbsFilter.java:138)at java.security.AccessController.doPrivileged(Native Method)at oracle.security.jps.util.JpsSubject.doAsPrivileged(JpsSubject.java:324)at oracle.security.jps.ee.util.JpsPlatformUtil.runJaasMode(JpsPlatformUtil.java:464)at oracle.security.jps.ee.http.JpsAbsFilter.runJaasMode(JpsAbsFilter.java:121)at oracle.security.jps.ee.http.JpsAbsFilter.doFilter(JpsAbsFilter.java:211)at oracle.security.jps.ee.http.JpsFilter.doFilter(JpsFilter.java:71)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at oracle.dms.servlet.DMSServletFilter.doFilter(DMSServletFilter.java:163)at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:60)at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3751)at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3717)at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2286)at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2185)at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1499)at weblogic.work.ExecuteThread.execute(ExecuteThread.java:263)<!--EndFragment-->