After killing the Ender Dragon gateway did not appear. After that i tried to reset the values in level.dat file (DragonsKilled and PreviouslyKilled) and kill the dragon again but that didn't help either. On a separate backup i tried to kill the dragon multiple times; none of the gateways appeared. gateways placed by /setblock work fine.
Environment
Win 10; Java version 8 update 151 (build 1.8.0_151-b12) 64bit
Dupe of MC-184482