Windows Defender often blocks older games from writing to the Documents folder. Search Windows for "Ransomware protection" and open it. Click Allow an app through Controlled folder access .
Add prototype2.exe to this list to allow it to write save files. prototype 2 failed to save data fix
Alternatively, temporarily disable to verify if security software is the cause. 2. Run as Administrator & Compatibility Mode Navigate to the game's installation folder. Right-click prototype2.exe and select Properties . In the Compatibility tab, check: Run this program as an administrator . Windows Defender often blocks older games from writing