My cells show "Could not initialize class org.opengis.wrapper.proj4.PJDatum"

The Proj.4 library has not been found or can not be loaded. Make sure that Proj.4 version 4.8 or above has been installed prior to the demo add-in. It may be necessary to compile Proj.4 with the --with-jni option.

MacOS users may see a message like "no suitable image found. Did find: ..., but wrong architecture". In such case, make sure that the Proj.4 library has been compiled for the right architecture (64 bits, 32 bits, Power PC). Note that if the installed version is a 32 bits software, then the "CFLAGS=-arch i386" flag may need to be specified even if the host machine is 64 bits.