The "lc_field_descriptionex" phrase isn't translation on "Configuration > E-commerce > Search" page.
Translate phrase to say "Description Exceprt".
Prior to introduction of "lc_" phrase prefix (phrase used on both Front-End and Admin Console) the phrase was named "lu_field_descriptionex" and was present in language pack of "advanced" theme. It still is present there.
Need to investigate what happened and move other missing phrases if needed.