Some of us need to run this on 8.5.3 , so i used the old template.
But: The search box works if you enter a search term and use the Enter key to start searching. If you click on the button with magnify icon the search fails with null (on a 8.5.3 server).

I found an easy fix: edit prtTitlebar, switch to Source Pane, and look for this line:
>xp:eventHandler event=“onclick” submit=“true” refreshMode=“complete” id=“eventHandler4” execMode=“partial”<
change to

>xp:eventHandler event=“onclick” submit=“true” refreshMode=“complete” id=“eventHandler4” execMode=“complete”<

now it works.