To get the Shimaden Sr50 controllers to work with version 5, you must put them into the Noml protocol mode on the front panel of the controller.

If the controller is in the Srfp mode, Find Stations will be able to find the controllers, but the MicroScan driver will not.

The Noml protocol mode is the SR50 mode for Version 5 / Shimaden Lite.
The Srfp protocol mode is the SR50 mode for Version 4.

This is set in the Comms settings on the front panel of the controller, the PrtC screen.