I'm another victim of the bug. Same thing, something happens that triggers the bug, then, when I enter a cell with mole rats (or other enemy that have the "hide underground" abiliity) and get detected by that enemy, and after that I try to save the game or change the cell, the game freezes.. Also, once the bug starts, the bug happens to all cells with mole rats. I'm using A LOT of mods, in fact the maximum amount of mods allowed. Which includes: Horizon, Place anywhere, WheelMenu, UFO4 Patch, SalvageBeacons, AAF, MCG, Homemaker, EnhancedLightsandFX, BostonFPSFix, AdvancedAITweaks, Unlimited Companion Framework, Unique NPCs - Creatures and Monsters, and yes Sim Settlements (3 in 1 + Conqueror). PS: I don't use any Scrap Mod apart of Horizon. I already started several Fallout 4 games, but that's the first time this happens to me. And between the last time I played without this problem and now, the only mod I added was WheelMenu (I don't know if it's related, probably not). I also tried several methods to try to solve the problem, but apparently something happens with the Save file, and when it does, that Save File is forever broken. I also confirm the strange non-aggressive behavior of the mole rats when the bug is active. I believe that something in the broken save file generates a conflict between the mole rats' AI inside the cell and some specific function used in the script of these mods, which in turn when accessing the save file freezes the game. That explains why disabling a specific mod can solve the problem. In short: Based on what has been said here, and on my personal experience. I believe the "mechanism" is as follows; Normal Save File -> (*) ??? ->Broken save file-> enter a cell with mole rats -> be detected by a mole rat -> try to save or exit the cell -> game freezes; So, there is a unusual and rare event that happens in (*) which I have no idea what it is (probably related to some combination of mods that use a lot of scripting that when happens creates a corrupted save file that triggers this bug), and as far as I know there's no fix for it, apart of disable a mod or specific combination of mods that varies from person to person. Or, of corse, to use another save file. Although I believe disabling a mod doesn't "fix" the bug, it just avoids the conflict it generates. Like, In my understanding, the problem is caused by a broken save file. And yes, this broken save file is caused by some mod or set of mods. But disabling the mod after this will not "unbreak" the save file. But anyway... I'll try the solution posted earlier here to Set max scripts in Sim Settlements to 0 to avoid the bug from trigger. But again, I confirm that after the bug has triggered, this solution doesn't solve the problem.