ime not sure if its a issue on anyone elses server but ive had reports from players that zombies are not spawning on the dangerous treasure event at supermarkets which in turn stop s them being able to open it as there arent any zombies to kill  ime using a 4k map and its procedual 

"Require All Npcs Die Before Unlocking": false,
"Unlock When Npcs Die": false
changed the top one as a quick fix for now