double post because i don't want to constantly edit my previous post.
i added more to my waterfall, and i accidentally made an invisible block.
I couldn't jump while on the block (although you could do a double jump off of it if you jump onto it first), nor could I delete it or put anything on top of it. What happened was, I somehow managed to place a block inside of another one by rapidly clicking (with a block selected) where I wanted to place the block. I'm guessing I was able to place the second block a split second before the first block solidified. When the two blocks were placed inside each other, I was confused, because highlighting it also highlighted the one below it. When I tried deleting the doubled up block, the block and the one below it vanished, but I could still collide with a ghost block. I couldn't highlight it or put a block in the space. Luckily, it became a real block again when I left and rejoined the realm.
