Hi Maik,
there was a reorganization of J2EE projects in NetWeaver Developer studio between 6.30 and 6.40 versions. In 6.30 there used to be both EJB Project and EJB Assembly Project (same for the Web projects by the way). From the 6.40 on, the functionality of both projects was combined in a single EJB Module project (Web Module project, respectively).
There is a migration guide describing how to port your NWD projects to the newer version. You can find it here:
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/com.sapportals.km.docs/documents/a1-8-4/migration guide from web as 6.30 to 6.40.pdf
Hope that helps,
Ivo
Add comment