OneDrive often takes over Documents folder, causing permission conflicts.
Prototype 2 was designed for Windows 7/8, not Windows 10/11.
If absolutely nothing works, use this community-verified workaround: prototype 2 failed to save data fix
Create a brand new Windows User Account (Local, not Microsoft).
It is a brutal fix, but it guarantees a 100% save success rate because you bypass all legacy permission conflicts from your main profile. It is a brutal fix, but it guarantees
The data save failure in Prototype 2 has been resolved via Build v0.2.1-hotfix. The root causes (serialization logic and file pathing) have been addressed, and rigorous testing confirms that data persistence is now stable. The team is proceeding with development on Prototype 3 with updated protocols to prevent recurrence.
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[Your Name] [Your Position]
Third-party antivirus (Avast, Norton, McAfee, Bitdefender) may quarantine or block write access. This is the most common solution.
This is the most common solution.
Prototype2.exe → Properties → Compatibility tab.