Hi again, sorry for the late.
That exception is the only one in my Log Viewer.
Here are some data from my development :
<helpValuesSearchMapping name="ValueHelpWithFunctionModule"
shlpName="IBO_SEARCH_USER_PERSON" table="">
<parameter name="NID" field="BNAME" descriptionField="" />
</helpValuesSearchMapping>
<helpValuesSearch name="ValueHelpWithFunctionModule"
type="list" description="Hierarchy Catg" maxRow="100">
<method name="getHelpValues" type="backend" />
<parameter name="NID" description="" valueDescriptionKey="" />
</helpValuesSearch>