Dear Devs,

JabRef 5.0.0-dev--2019-10-31----ac7875a96
Linux 5.2.0-0.bpo.3-amd64 amd64 -- Debian 10 Buster
Java 12.0.2

Steps to reproduce the behavior:

1. Add a list of abbreviations
2. txt files are not seen
3. I converted my list in csv
4. Import csv file
5. JabRef don't see any abbreviation and abbreviations don't work

My list is this, but I use a file in my machine: https://github.com/JabRef/abbrv.jabref.org/blob/master/journals/journal_abbreviations_annee-philologique.txt

Best wishes,
Domenico

P. S.: I proposed a new italian translation for the corresponding item in the menu (#5553)