MIST - Error in function "checkSpawnedEventNew"

Hello,

In one of my missions, when started on dedicated server, after some (long rather) time the MIST starts to flood into log following error:

stack traceback:
   [C]: ?
   [string "c:\temp\DCS.openbeta_server\/~mis00005BBB.lua"]:641: in function 'dbUpdate'
   [string "c:\temp\DCS.openbeta_server\/~mis00005BBB.lua"]:845: in function 'checkSpawnedEventsNew'
   [string "c:\temp\DCS.openbeta_server\/~mis00005BBB.lua"]:1154: in function <[string "c:\temp\DCS.openbeta_server\/~mis00005BBB.lua"]:1147>
2020-09-15 12:07:29.983 WARNING LOG: 4 duplicate message(s) skipped.
2020-09-15 12:07:29.983 ERROR   SCRIPTING: Mission script error: [string "c:\temp\DCS.openbeta_server\/~mis00005BBB.lua"]:829: attempt to index a nil value

The script itself I am attaching to this post.

Question is what can be the reason of such behavior and how to debug or investigate it?

EDIT: Sorry for misleading subtitle, it's about function checkSpawnedEventsNew

~mis00005BBB.lua

It was a bug that was present on the very outdated master branch of mist, but was fixed on the development branch. Using mist 4.4 should fix the issue.

https://github.com/mrSkortch/MissionScriptingTools

Indeed, I was using the older MIST version. I'll exchange scripts and give it a ride. Thank You!