I killed chupacabratch (Athenas) before I received Quest to kill it. Now he doesn’t spawn and Quest is still active …Green, .
Sorry this is a tad late, BUT! have you tried quitting your game and reentering? most hostiles will only spawn once per session so by quitting the game and rejoining, it should cause all the hostiles you killed in the session prior to respawn!
Yes. Restart WHOLE game Helps. Not just reload map.