When the Indigo client detects it is not current for the server it is connecting to, it pops up a window with a warning message:
This version of the Indigo client application is not compatible with the Indigo Server. Make sure you have run the latest Indigo installer on both your server Mac and all client Macs
However, there is no link to the software download page in that window or in any of the menu bar items. A link to the software downloads page would be a "nice to have."