Fossilize bugs all the time now ... not sure what corses it, but it make it so that you cannot use the skill on a target that is not CC immune. After this have happened it don't work until you die or change skills and use skill (you put in insted) and then change back to fossilize. It happens most around templars and necromancers but also happened agenst others.
So rigth not that skill is useless because when you use that skill on a build, you are making your build more squizzy because you sovive longer when you mass CC the enemy you figth. Please make it work probebly again.