[Dup] Dev 2521 Error “attempt to call method ‘is_active” (a nil value)

Every time i load new map i can play untill i save the map. After which i get this error which causes some of my hearthlings to stop doing anything. And i don’t mean they walk around doing nothing. They are literally statues frozen in place.

System: Win8.1 Pro
Intel Core i5 @ 3.3GHz
Nvidia GTX570 w/ 1GB GRAM

develop-2521 (x64)
radiant/controllers/time_tracker_controller.luac:7: attempt to call method ‘is_active’ (a nil value)
stack traceback:
radiant/modules/events.luac:68: in function 'is_active’
radiant/controllers/time_tracker_controller.luac:7: in function 'set_now’
radiant/controllers/time_tracker_controller.luac:20: in function 'increment_now’
radiant/modules/timer.luac:6: in function 'self’
radiant/modules/events.luac:80: in function <radiant/modules/events.luac:78>
[C]: in function 'xpcall’
radiant/modules/events.luac:78: in function 'trigger’
radiant/modules/events.luac:97: in function '_update’
radiant/server.luac:19: in function <radiant/server.luac:17>

I moved a post to an existing topic: [d-2494] Error in time_tracker_controller. Citizens stuck in floor