audiveris-ng currently depends on the old jai-imageio-core-standalone, version 1.2 from 2014. Its (no longer maintained) code is still located at Java.net and will disappear very soon (java.net and kenai.com will go down April 28, 2017).

There is a fork of this project at Github. The proprietary Sun package prefix com.sun.media has been replaced with com.github.jaiimageio. There is a newer version - 1.3.1 from 2015.

I propose to switch to the github version.