Invalid character in the given encoding. Line 1, Position 25.

I am trying to convert and upload my French and German term bases created in Atril Déjà Vu to SDL Multiterm. I first exported the DV files to Excel and then used Glossary Converter to convert them to sdltb files, but when I try to load these into SDL Multiterm I get the following error message: "Invalid character in the given encoding. Line 1, Position 25." I am a relatively new user of Trados, so may be missing something obvious to more experienced users. Grateful for any assistance. Geoff