I tried burning an ISO to a DVD, and burning stopped at 99% with an error saying: "Fatal error during recording: Invalid argument" I was using the dvd+rw-tools 'growisofs' in Mint 19.1 "Tessa" MATE (64-bit). After giving up with finding a solution, I decided to see when the k3b page (k3b.org) was last updated. It was last modified on 6 January 2012. That's definitely outdated! If you're also having problems with k3b, try Brasero instead. It's more up-to-date, and I managed to successfully burn an ISO to a DVD.
First time I tried this it crashed adding simple MP3 files but I fixed this by installing the codecs: sudo apt-get install libk3b6-extracodecs
Such a cool application, sadly the package in the repository is a bit old: The newest version is something like 2017.04.
Absolutely the best burning software (and you can equalize songs). For Linux Mint it is the only total solution. Tested at many tasks. Safe, easy and really effective!