Windows 10 Home 64 bit.  Java 1.8.0_51 or Java 8 version 161 When I first started the world there were hostile mobs, even 2 dragons at night. For some reason, after the 2 dragons died when the sun came out the world would not spawn any more hostile mobs.  I've even tried to reload this world creating it from the seed and there were still no hostile mobs in it. Here is the seed -1306588647538124419. The dragons (which were amazing) location was at block -480 / 71 / -1067. I tried another world and only 1 spider tried to attack me, but that was it.  There were no other hostile mobs to be found. The other outstanding mobs were present like turtles, etc, but no fish in the water either. Thank you.