As you might know you are able to change things like "Grass Block" into whatever you want, defined in the (in this example) en_US.lang file in assets/minecraft/lang. One time it worked but now It does not work anymore.
Comments 3
Are you sure you are loading them and setting the lang to the one you modified in the game? Also make sure they are in the correct directory inside the resource pack, and that the file name is the same
Lowercase your file name.