So I've been having this same issue, and I've talked to a bunch of other people who are experiencing it. We are pretty sure we've tracked down the cause -- strCount in the Papyrus block of the save files. https://www.uesp.net/wiki/Tes5Mod:Save_File_Format/Papyrus The strCount field is only 16bit. What seems to happen is that in a heavily modded game, strCount gets quite large, and eventually overflows. DynDoLod just happens to add a lot of strings to this section (I think every single script instance's properties and variables get added, so 13 entries per LODObject!), so it is frequently the mod which pushes a save file over the edge and causes an overflow. So it seems like there's no easy fix except to run fewer mods... unless someone makes a patcher for Skyrim that changes strCount to be 32bit.