FSX "SEARCH ADD-ON SCENERY" missing all scenery

On a new Windows 10 PC I have loaded FSX plus Accelerator and several aircraft, airport and scenery DVDs. I can fly around without a problem except the scenery is default. I know I successfully loaded scenery as when I go to Scenery Library I see 156 areas listed (the default plus the add-ons). One installed in the default C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\Addon Scenery and the others elsewhere - all are visible in the library and can be edited.
But when I go back to the main screen and initiate a free flight then push the Current Location Change... button I am shown just the default scenery. There is a radio button "Search add-on scenery" but when selected I get nothing shown - just empty panes. How can I enable the loaded scenery please ?
I have installed two planes and they are selectable, but my airport and scenery are hiding. I just don't know how to proceed to track down the cause of them being shown in one part of the program but not in another.

But when I go back to the main screen and initiate a free flight then push the Current Location Change... button I am shown just the default scenery. There is a radio button "Search add-on scenery" but when selected I get nothing shown - just empty panes. How can I enable the loaded scenery please ?
I have installed two planes and they are selectable, but my airport and scenery are hiding. I just don't know how to proceed to track down the cause of them being shown in one part of the program but not in another.
