Jon won’t see or respond to this until he releases an update. That could be in a day or a month

If you want faster service email him the last 3 saved games, crash log and print screen of the crash to contact@conifergames.com

I ran into the same bug; after some modding tweaks, I was able to go 200+ turns without seeing it (was running into around turn 100 before) The latest version of HOM (1.2) should have addressed it. Give it a try and let me know if the issue persists. (You might be able to continue from autosave's previous turn using the new mod....no guarantee tho)

https://www.moddb.com/mods/hom/downloads/version-1213#downloadsform

I am getting exact same error with that key thing.....I think my turn is around 219 when it crashed.