So I use a summon generator to try to make a cool mob, and I copied it right. So I pasted it into a command block and ran it, the mob spawned then vanished-almost instantly. Some simple configurations work, but most don't. My friend's device could do it-why couldn't I?
On minecraft 1.8/1.9, I tried both
Please provide the exact command used.
Make sure that, when summoning a hostile mob, the game is not on peaceful mode.