I'm having exactly the same problem described in this topic:
http://fractalsoftworks.com/forum/index.php?topic=12891.15Game freezes late in the game. No crash, just a complete freeze up that then results in the 'not responding' error from windows which I need to ctrl+alt+delete to kill the program. Therefor nothing shows in the error logs.
However, I did keep the save! How should I attach it as it exceeds the file limit?
Mods UsedSpoiler
Blackrock Drive Yards
Combat CHatter
Console Commands
Diable Avionics
DynaSector
GraphicsLib
InterstellerImperium
LAzyLib
Leading Pip
Nexerelin
Portrait Pack
Save Transfer
Ship & Weapon Pack
Underworld
Version Checker
I too found that deleting the bounty line from Dynasector's events.json in the campaign folder solved the problem. I have not a clue why. However, if you start a
new game no 'named' bounties will ever generate. If you edit this in an existing save then bounties generate normally and crashes are avoided.