If you have purchased 4D Server Developer Edition, it comes with 2 4D ODBC Plug-in client connections. You will not be able to see these client connections directly under the "License Number Entry", just as you are not able to see the 2 default 4D Client connections. It is assumed that 4D Server Developer Edition comes with 2 4D Client and 2 4D ODBC connections. If you want to add 2 additional 4D ODBC Plug-in connections for a total of 4 connections, you cannot simply purchase the base 4D ODBC Plug-in license, instead you will need instead to purchase 2 one user expansions. This is because you already have the base license - it is included with your developer edition. If you try to attach a regular 4D ODBC license to the 4D Server Developer Edition, you will find that the serial number will be accepted by the server - making it seem as though you have a total of 4 ODBC connections. However, 4D Server will only recognize a total of 2 connections. To add ODBC connections after installing the 4D ODBC plug-in, you will have to purchase 1, 5 or 10 user expansions.