Blockstate null texture

I'm trying to make a simple crop that has 6 states. It was working last time I launched the Minecraft and I didn't feel as if I changed anything related to the model data.

The problem is that the original state of the block is working just fine but changing the state to any of the other blockstates I have, display a default null texture block. This is strange because I use a built-in model (Cross model).

Note: It was working at one point before I made a couple of procedures but besides those, I changed nothing.

Why is this happening. I just want to make a crop. Please help.