Unexploded TNT/White blocks falls from sky when so much TNT gets blown up at a time

So about a month ago, i finished my TNT project, which was to be 256 x 256, which equals 65,536 TNT to be placed down. It got finished, and i was ready to ignite the TNT. It was cool until i noticed that some TNT didn't get to explode and started to fall from the sky, it was strange. The unexploded TNT was a bright white colored block that you could pass through, and you couldn't remove it at all. I nicknamed it the White Block. I hope this bug gets fixed soon in the next update.