Error "The selected termbase object does not exist. It may have been deleted" when trying to export entries

Hi, what am I doing wrong if following error occurs when carrying out the "Export Entries..." action : "The selected termbase object does not exist. It may have been deleted"? So it seemed that I can ignore this error, because I can do exports, for example, as usual. However, I cannot load export definitions that are not yet displayed in the selection list of the "Termbase Catalogue" dialog. I use a rather old version of MultiTerm (6.2.0.267).