A widespread, consistent bug causes saves for Cyberpunk 2077 to become irretrievably corrupted if they exceed 8MB in size. It’s not clear exactly how this works, but a help page from CD Projekt RED asks players to “Please use an older save file to continue playing and try to keep a lower amount of items and crafting materials.” According to CDPR, though the save file size limit may be increased in a future patch, the corrupted files will remain corrupted.
So you can craft, but also, don’t craft like it’s the whole game. Do some other stuff too.
It does seem that one way to definitely do this to yourself is to use an item duplication glitch currently in the game, per CDPR: “If you have used the item duplication glitch, please load a save file not affected by it.”
So don’t use the glitch and don’t craft exhaustively if you want your save to live forever.
Players started to report this glitch earlier this week, and by Saturday it had become clear that any save file over 8MB was corrupted. Explanations likely have something to do with the game running out of index space allocated for crafted items due to players duplicating, I don’t know, a few thousand grenades. Or spending all your time gathering a large amount of trash and using it to craft “hundreds” of grenades, as I saw one player report.