Work with changed objects returned by IF_GENIL_APPL_INTLAY~MODIFY_OBJECTS

Hi Experts,

I am trying to enhance the existing GenIL-Implementation for the org model and for that I have created class ZCL_CRM_OMIL_COMP that extends standard class CL_CRM_OMIL_COMP. When objects of the org model are changed method IF_GENIL_APPL_INTLAY~MODIFY_OBJECTS is executed and I have overwritten this method in my class as follows since I need to work with the list of changed objects:

method if_genil_appl_intlay~modify_objects.

data: ls_changed_object type crmt_genil_obj_instance,
ls_key type crmt_genil_orgheader_key.

try.
call method super->if_genil_appl_intlay~modify_objects
exporting
iv_root_list = iv_root_list
iv_return_root_list = iv_return_root_list
importing
et_changed_objects = et_changed_objects.

endtry.

loop at et_changed_objects into ls_changed_object.

if ls_changed_object-object_name = 'OrgUnitEmployee'.

call method cl_crm_genil_container_tools=>get_key_from_object_id
exporting
iv_object_name = ls_changed_object-object_name
iv_object_id = ls_changed_object-object_id
importing
es_key = ls_key.

endif.

endloop.

endmethod.

During execution this coding yields an exception of type CX_CRM_GENIL_GENERAL_ERROR within method cl_crm_genil_container_tools=>get_key_from_object_id. Can anyone explain to me why and what I can do about this?

Thanks a lot!

Jens