Final reports and system reports still use Crystal Reports files (*.rpt) as the template. The server on which LIMS-plus v3.8 is running must have a 64-bit ODBC connection configured to the database just like prior versions of LIMS-plus. (Note that older versions of LIMS-plus used 32-bit so you may need to create this manually if you skipped the step in the installer.)
So that you don't need to modify all of your reports, it's recommended you use the same ODBC name (DSN) that was used for your older version of LIMS-plus.
Note that the application expects all report templates to use integrated security; that is, the ODBC connection must use Windows NT Authentication (Integrated Security) and NOT SQL Authentication.