When I put the four specific blocks: white concrete, black concrete, yellow concrete, and ornate cobblestone, all from the Chisel Mod, they disappear and the game shows the coordinates of the block I'm looking at. But other blocks are no different and work correctly. How do I fix this? I think a command did this, because I was testing commands. These blocks were in my hand when this problem started, it seems that it only affected the blocks that were in it.