Use the Flexible search path settings form in the General Settings module (Flexible search paths folder) to set the search path you actually use for a particular application by marking it as the current search path. You may have multiple search paths, for instance, one for this year, and one for next year, when you will be changing the structure of the search path. In this case, mark this year's search path as the current search path.
Isah will look up the data required using the current search path, unless another search path has been specified elsewhere (for example in the service contract version).