Solution : https://service.sap.com/sap/support/notes/1556808 (SAP Service marketplace login required)
Key words : 
previous releases return null, cmi model reason, fix caused problems, context model attribute, returns null, terms context, primitive types, special case, existing projects, solution apply
Related Notes : 
       
| 1501448 | Download Web Dynpro SCAs in NetWeaver 7.3 |