There is a thread touching on the savegame issue, but what I don't get is why I have a 6MB save game, but others who are exploiting the game have 4-5MB saves, some with many more hours than I do. I see one person made this post now in the CDPR thread on their website:
Tested the duping glitch at a terminal; can confirm, it does NOT increase the save file size.
Made 100 Epic and legendary components, a few weapons and about a thousand of the silly paintings you can sell for money. Save file doesn't change size.
Ironic since our games were corrupted by using game mechanics rather than exploits.
As for natural file size increase: side missions such as the gigs and ncpd missions account for about 2kb each. The main missions, estimate about 50-100kb depending on the mission. (at least act 1 and the beginning of act 2. Havent progressed too far).
And I also tested exactly this, nada, same size, and I did push it. My original game which is clean, played normally, without even investing into crafting is 6MB.
I am still in the opinion that 1) the debugger was used to exploit the game at some point in time and or 2) not all game state's behave the same and that there is a variable which is behaving incorrectly (or erratically) in the respective instances.
Nonetheless, the CDPR moderators approached the situation, terribly. Almost everyone in the community testing this issue are coming to different conclusions, and many others are trolling. What is consistently resulting in a save game break is item duplication, but not everyone with broken saves are duplicating items, and this is also applicable to the vendor machine exploit.
As per the GOG troubleshooting guide,
Cyberpunk 2077 - Saved data is damaged and cannot be loaded.
Unfortunately the save is damaged and can't be recovered.
Please use an older save file to continue playing and try to keep a lower amount of items and crafting materials.
If you have used the item duplication glitch, please load a save file not affected by it.
The save file size limit might be increased in one of the future patches, but the corrupted files will remain that way.
but do note, the error prompt, according to many, was removed in patch v1.05.