I was building a house and every time I placed a block I expected it to appear and I could go about my business building. but instead I saw an outline of the block and it took awhile for it to appear, same goes for mining, I was digging down trying to get some cobble and while I was digging I phased through the stone block and it gave me an x ray view of a mine shaft and a buried desert temple, so the bug can be useful, and I didn't mention but you probably already guessed that the blocks still act like they should after being destroyed or placed but it takes awhile for them to relies there destroyed/placed, it is kind of annoying and my computer is really good, so I hope you understand what I'm typing so you can fix it. p.s. I don't think that is supposed to happen...