Travel request notification displays nothing(Blank page) for approving when it is opned by Manager

Dear SAP gurus,

Our employee raised the travel request in ESS in portal, the travel request notification comes in to Manager Inbox in portal, but manager unable to see the request for reject / approve , because when he double click the request notification to open it displayed blank page.

We are using  portal 7.3 EHP1 and ECC 6.0 EHP6.  For travel management i created another system with alias SYSTEM_TRAVEL name.For TM in r/3 we activated mentioned Business functions FIN_TRAVEL_1,FIN_TRAVEL_2 ,FIN_TRAVEL_3, HCM_ESS_WDA_1 AND HCM_ESS_WDA_2.

Our WF consultant uses JAVA task for applying,pending and rejecting the travel request.He used stranded task TS21000130 for approving the request (JAVA )

Please advice me how can i resolve this issue.

For your reference please observe the attached screenshot.

The UWL calling  below URL,

http://FQDN: <port>/irj/servlet/prt/portal/prtroot/pcd!3aportal_content!2fevery_user!2fgeneral!2fdefaultAjaxframeworkContent!2fcom.sap.portal.standalonecontentarea?NavigationTarget=ROLES%3A%2F%2Fportal_content%2Fcom.sap.pct%2Fevery_user%2Fcom.sap.pct.erp.ess.bp_folder%2Fcom.sap.pct.erp.ess.roles%2Fcom.sap.pct.erp.ess.employee_self_service%2Fcom.sap.pct.erp.ess.employee_self_service%2Fcom.sap.pct.erp.ess.area_travel_expenses%2Fcom.sap.pct.erp.ess.tripform&DynamicParameter=sap.xss.tra.PersNo%3D10054503%26sap.xss.tra.TripComponent%3DR%26sap.xss.tra.TripNo%3D0100000007&sap.xss.tra.PersNo=10054503&sap.xss.tra.TripComponent=R&sap.xss.tra.TripNo=0100000007&PrevNavTarget=navurl%3A%2F%2Fdc2de153e2803241d04df826927d053d&NavMode=1&CurrentWindowId=WID1359717979572 .

My question is that Travel request calling portal URl which is JAVA ? is this correct? if correct as a portal person i need to do any changes in portal ?. As of my knowledge from 7.3 onwards TM will work on only ABAP stack, but my work flow consultant done the tasks in Java and it is also calling java page from portal. TM is fully depend on R/3, if i am wrong please correct me.

Thanks in advance.

Kindly Expedite

With Regards,

Srinivas