I put an audio cd in the drive on my new 18.04 installation, started Rhythmbox, selected all and clicked "Extract". It extracted the first track and stopped. Whenever I try to rip more tracks, I get the message "Could not open resource for writing."
I tried to change the format to MP3, but then I'm told to install additional software, but not which software.
I tried to install Sound Juicer, and I should just have ripped my cd in Ogg Vorbis format, but I had to try and change the format to MP3, and now whenever I start Sound Juicer, I get a "Cancel or switch profile" dialog, but whatever I choose, Sound Juicer closes. I tried to uninstall it and install it again, but now that dialog comes up regardsless, and the program closes whatever I choose.
fre:ac works on my Ubuntu 18.04 system. I did not succeed with rythmbox, Amarok, asunder, audacious and sound juicer for getting mp3 files from my audio CD.
I encountered the same error (in Rhythmbox 3.4.2, German, it reads "Die Ressource konnte nicht zum Schreiben geöffnet werden") and noticed that it disappeared immediately after I had enabled the group write access to the music folder.