For your savegames going beyond 20mb and crashing this way it's to be assumed the environment you uses to mod is the real issue. I don't have a save game which fits the request, anyway it should be a clean savegame without mods. My advice for you and any other modder is to keep a clean game installation (a modder should know how to backup restore the relevant register part and create batch files to allow toggling between the modding environment and the playthrough environ). That procedure should grant two immediate advantages: 1 - be relatively sure the mod will work and be as independent as possible of external factors 2 - Allowing the test under heavily modded game installations. Of course the savegames (indeed all that fallout3 folder under (my) documents) should be included in the toggling too. Addendum: That multiple installation is possible and I had at least 3 sometime ago (albeit it was Oblivion instead Fallout3) ... One for a 1.1 patched version, another for the 1.2 and one, heavily modded environment I used to actual play and testing purposes. It's not caused from my mods, I haven't ever used placeatme command which is the cause of all problems, I always use persistence reference and moveto script, I neither use weapons that make ash piles anymore, yes they make larger the savegame, I messed up my game building my village with RTS, I used more than 300 obects among metal plates and stairs to build a floating city, but unfortunately I couldn't load savegames anymore