Some challenges in Skyblock world by Piki Studios are impossible to finish. Endermen don't drop ender pearls. Not a single one. Tested multiple times in different worlds under different settings but no single pearl was dropped. Also skeletons do not drop arrows.

I also think that netherportal from nether is bugged beacuse it teleports you into midair, but that's another story as this can be tweaked by player itself. Former drop issues cannot be. I am actually very dissapointed after playing the world for many hours finding out that I just cannot finish it...

Just for the record, the world link is: https://www.minecraft.net/en-us/marketplace/pdp?id=ddd2bcc0-0996-4031-993a-0f541266c3dc