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my savefile was for version x.28 then the game updated to x.29, is there anyway to make it "move" to the new version? or do i just start over?
second question is, is there any known way to enable super sampling with nvidia hardware? NVM, just enabling 4x4 super sampling in nvidia inspector worked.
no, factorio updates frequently, mostly small changes and bugfixes, and save files are (in my experience since 0.10.12) always preserved. Some changes between major updates might require you to redesign parts of your factory and then you might decide it will be easier to start a new game, but the save file will still be playable. Only time it won't be playable is if you try to use an earlier version of factorio.
True, you can simply load your save again, it will automatically be converted to the new version. That's usually no problem at all.
However, I believe you won't be able to use the replay feature for this save if the game had different versions across the save's lifetime. I'm not sure why that's the case, but it's no big deal to most people, I guess.
If your save isn't shown anymore at all, that's unusual. It should still be there.
Also, there is no x.29,
Current version is 0.12.28