Glossary Converter and Glossary Plugin Error

¡Hello, everyone!

I've recently downloaded the Glossary Plugin, as well as the Glossary Converter, so that I could use it when translating with Studio Trados 2019. I followed the instructions during installation and everything seems to be OK. I'm in fact able to create Termbases using the Add and Add (TM) buttons. Nonetheless, when trying to import an Excel file to create the termbase directly, the following error message appears. 

Could you help me?

Thank's in advance