I did the reverse engineering from SQL Server database. Now I am try to create a sql script based on what I got from SQL Server. My new target database is not SQL Server. It is probably Sybase database. It looks like I have to install the Sybase database before I can switch to Sybase by doing Model Update? Right now there is no OLE DB or ODBC Provider for Sybase on my machine yet. Why we need the target database physically exists on a design machine? It will be much simple for user just switch a target database without any connection to generate sql script.
My suggestion, try using the Simple Model Conversion instead. Go to File | Sync & Convert | Simple Model Conversion | select either Sybase ASE 12.5 or 15 in the “To Database” dropdown. Once the model is converted to Sybase, then you can generate the sql script by going to Model | Generate DDL Script.