Hi Saguaros,
thanks, now "smart search" works fine.
Note: Using only the Module "smart search" in the position "head-actions", it shows a magnifying glass and klick on it one can enter a search string. But no search results will be shown!
I additionally must create a menuitem, type "smart search".
Then the "smart search" works fine: The menuitem and also the Module.
Regards,
René