Solution : https://service.sap.com/sap/support/notes/514055 (SAP Service marketplace login required)
Key words :
<deployfolder>\irj\web-inf\plugins\portal\logs\usermanagement, log \irj\web-inf\plugins\portal\logs\workplace, user management log file, sapportals\usermanagment including subfolders, csn customer message effectively, portal/unifier/um, terms user management, respective trace logs, symptom development support, prerequisites dear customer
Related Notes :
525294 | How to create a Portal trace |
456348 | EP 5.0: Central Note for Support |