keep losing my savegames

hi there
i keep loosing my savegames. i lost my big one after the biome update. after v218.1 i could open it again, but all the dino Skeletons where broken.

whatever.

i’m still losing test savegames when testing my mods. i don’t have any core mods. just adding new things like a stone crusher or new set of ramps and rails.

is there something to consider?

when i start the game and add and remove mods before playing: does that already reset my savedata?

No, your save data is not stored separately regardless of mods, even TC ones. You have to make backups manually.
However, changing mods mid-game could cause the save file to be read incorrectly and removed as “corrupt”.