Once again: downloading from the link worked well untill a week ago !! So you did support the mp3 recordings there !
It worked fine only a week ago or so from this site with savefrom !!!
You said the add-on is out-dated. download of mp3 dit not work anymore, so I tried to update for Firefox. Did not work. today I removed the add-on , closed Firefox ( I always have the latest version, now 61.0.1), add added again. No result, cannot download files. What is going on???
Windows 10 Home 32 bit, Firefox 61.0.1
This is the site: https://www.nporadio4.nl/cds/busch-trio-dvorak-piano-quintets-bagatelles?utm_source=webpower&utm_medium=email&utm_content=Beluister%20CD%20van%20de%20week%3A%20Dvo%C5%99%C3%A1k&utm_campaign=nieuwsbrief%206%20augustus-%20VERSIE%20A%20%28Copy%2020180806-14%3A43%29
Earlier it worked fine downloading from this site.
Customer support service by UserEcho