There was a lot of salt-tossing and use of black magic with SH3 saves, but with SH4 having a much more manageable campaign size for the Save, the only aspects that should affect a save is the immediately roughly 30nm radius around your submarine. Every other bit of data is still in a spreadsheet (database) and hasn't been drawn. As I mentioned, those "timers" are a big thing, as is the save file size, as KaleunMarco mentions, especially if you Save a Replay - but can also happen when corruption occurs in the Save file. The rest of Save file issues are usually player-inflicted, by activating and deactivating mods, whilst forgetting which Save is for which mod
- been there done that, as they used to say. That is about the fastest way to not only ruin a Save point, but maybe even cross-contaminate the game install also.
MultiSH4 is our friend, as is JSGME's "Generate snapshot of game files", along with
Rockin Robbins SH4CMS, which can also be manually accomplished with 7zip and other archiver programs...
