Engine Error - 'report traceback'

No specific actions. The error popped up during normal gameplay.

Steps to reproduce:

release-696 (x64)
Unknown C++ exception
stack traceback:
radiant/modules/common.lua:237: in function 'report_traceback’
radiant/modules/common.lua:248: in function <radiant/modules/common.lua:242>
[C]: in function ‘get’
…/upgrade_equipment/find_equipment_upgrade_action.lua:47: in function 'fn’
radiant/modules/events.lua:288: in function <radiant/modules/events.lua:285>
[C]: in function 'xpcall’
radiant/modules/common.lua:257: in function 'xpcall’
radiant/modules/events.lua:285: in function 'trigger’
radiant/modules/events.lua:370: in function '_fire_async_triggers’
radiant/modules/events.lua:445: in function '_update’
radiant/server.lua:61: in function <radiant/server.lua:58>

Expected Results:

Actual Results:



Version Number and Mods in use:
Release-696 (x64)

System Information: