Dev 2513 Error popup "grizzled traveler appears"

The bug appears to be triggered by the start of an event, "grizzled traveler appears"
System:
Intel Core i7 @ 2.4Ghz
12GB RAM
Nvidia GTX650M 1GB

develop-2513 (x64)
stonehearth/lib/i18n/i18n.luac:11: attempt to concatenate a nil value
stack traceback:
radiant/modules/common.luac:32: in function <radiant/modules/common.luac:32>
stonehearth/lib/i18n/i18n.luac:11: in function 'format_string’
stonehearth/lib/game_master/game_master_lib.luac:5: in function '_compile_bulletin_text’
stonehearth/lib/game_master/game_master_lib.luac:9: in function ‘compile_bulletin_nodes’
…er/controllers/encounters/dialog_tree_encounter.luac:4: in function ‘start’
…rvices/server/game_master/controllers/encounter.luac:22: in function ‘start’
…rth/services/server/game_master/controllers/arc.luac:49: in function ‘_start_encounter’
…rth/services/server/game_master/controllers/arc.luac:41: in function ‘_trigger_edge’
…rth/services/server/game_master/controllers/arc.luac:17: in function ‘trigger_next_encounter’
…me_master/controllers/encounters/wait_encounter.luac:11: in function '?'
radiant/modules/common.luac:86: in function 'invoke’
radiant/controllers/timer_controller.luac:29: in function 'fire’
radiant/controllers/time_tracker_controller.luac:9: in function <radiant/controllers/time_tracker_controller.luac:9>
[C]: in function 'xpcall’
radiant/controllers/time_tracker_controller.luac:9: in function ‘set_now’
…earth/services/server/calendar/calendar_service.luac:112: in function 'fn’
radiant/modules/events.luac:79: 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>