Solution : https://service.sap.com/sap/support/notes/207807 (SAP Service marketplace login required)
Key words : 
additional key words uagui, symptom uagui hangs, setenv libsocket_bsd noas, jre -native cp, uagui start, prerequisites conversion, bsd sockets, connection, environment
Related Notes : 
       
| 390062 | Additional information about upgrading to 4.6C SR2 |