ERwin r9 introduced a new architecture for the Workgroup Edition repository (aka Model Mart). There is now a web server acting as a broker between the Mart database and the Data Modeler. This has particular implications for Mart reporting.
Mart reports are now delivered as web services rather than SQL queries. You can access these from within ERwin DM Workgroup Edition when connected to the Mart from the Tools menu, Mart Reports option.
If you try to run these reports from outside ERwin DM, however, you will run into problems. That is because the data source urls specified in the report definitions are wrong. When you run the reports from within ERwin DM, you are forced to enter your login details for the Mart Server (again), and these details (port number, username and password) are used rather than those embedded within the datasource url. You need to create new data sources in Crystal Reports with the correct port number, username and password to allow you to run the reports from outside of ERwin DM. This is documented here, but note that the port number specified is misleading. Be sure to use the same port number you use to login to the Mart Server from within ERwin DM (81870 by default).
Of course, not everyone wants to use Crystal Reports. It is often seen as just a stepping stone to the format you really want, e.g. Excel or HTML. The good news is that you can consume these web services directly from your browser, by entering the correctly structured url in the address bar, or from within Excel by using the same url in the Get External Data group, From Web option.