Solution : https://service.sap.com/sap/support/notes/609364 (SAP Service marketplace login required)
Key words : 
usr/sap/<sid>/sys/global/sld/model, terms sap system landscape directory, administration -> server details -> dataabout 21, system landscape directory, sld model files, model files fails, xi exchange infrastructure 2, upgrade cr content, 'instancebuffersize' profile parameter, inadequate work memory
Related Notes : 
       
| 620103 | SAP Exchange Infrastructure 2.0 SR1 Installation | 
| 619484 | SLD: java.lang.OutOfMemoryError | 
| 520484 | Memory settings have no effect for J2EE-Server |