Once I tried to plant the seeds and it didn't work, I destroyed the grass blocks and re-harvested them. The problem remains. I can break other wheat blocks, and harvest those. But the area of about 150 blocks does not allow me to place any seeds down. I was holding nothing in my hand, so it was my bare fist when I destroyed the one wheat block. I also have tried to close Minecraft and re-open it. It has not worked. That is all the information that I have.