Right-click Prototype 2 in Steam and select Properties . Navigate to local files: Click on the Installed Files tab. Run validation: Click Verify integrity of game files .
If you bought Prototype 2 on rather than Steam, you have a unique problem. The GOG version is notoriously DRM-free, but its cloud sync implementation is fragile. If you see the “failed to save” error on GOG:
Look at the bottom of the tab for the Attributes section.
Here’s a complete review of the most effective fixes for the error on PC (Steam, typically Windows 10/11). prototype 2 failed to save data fix
Open Steam, right-click Prototype 2 , hover over Manage , and select Browse local files .
Modern Windows environments treat Program Files as a protected system directory. When the game attempts to write a save file (e.g., slot1.sav ) to a folder inside Program Files , the User Account Control (UAC) blocks the write operation. The game engine does not possess the exception handling to request elevated permissions; it simply detects the write failure and throws the generic "Failed to save data" error.
In the tab, check Run this program as an administrator . Right-click Prototype 2 in Steam and select Properties
In that folder, find prototype2.exe .
Click Change settings for all users at the bottom and check Run this program as an administrator there as well to ensure it sticks. 2. Configure Windows Security (Controlled Folder Access)
Because the game cannot write to your hard drive, you risk losing hours of gameplay. Fortunately, this issue is almost always caused by system permissions, conflict with cloud synchronization, or modern Windows security features. If you bought Prototype 2 on rather than
This issue is most prevalent on modern Windows operating systems (Windows 10 and Windows 11) due to tightened security permissions regarding the Program Files directories and the depreciation of legacy DirectX runtimes.
For extra stability, also check the box for and select Windows 7 from the dropdown menu.
