OS: Mac OS 10.11.1
I installed ImageJ and was going to display the example image "flybrain.tif" using "3D Viewer" under Plugins -> 3D. However, the 3D viewer doesn't launch.
I searched around and realised that it could be a problem from java3d, so downloaded java3d from https://java3d.java.net/binary-builds.html. I placed the three *.jar from java3d under /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/jre/lib
and added the paths to the ~/.bash_profile.
The 3D viewer still doesn't start. Anything else I can try? Many thanks!
I have a similar, not identical setup (Mac OS 10.11.2, jdk 1.8.0_66) and I am able to open the Fly Brain in 3D viewer using Fiji.
In Fiji, I activated the update sites for ImageJ, Fiji, and 3D.
You might also try posting the question at the ImageJ forum.
Hope this helps.