Find prototype2.exe in your installation folder (e.g., ...\SteamLibrary\steamapps\common\Prototype 2 ).

If Controlled Folder Access is turned On , click Allow an app through Controlled folder access .

Add prototype2.exe to this list to allow it to write save files.

When a Prototype 2 (e.g., an object created with Object.create, a class instance, or a UI/UX prototype labeled “prototype 2”) fails to save data, the problem can come from several layers: the model/instance itself, serialization, persistence layer (localStorage, IndexedDB, backend API), network issues, or UI logic. This guide walks through a structured troubleshooting and fix process, with concrete checks and code patterns you can apply.

If your Documents folder is on a network drive or read-only, move saves to a local folder:

To fix the "failed to save data" error in Prototype 2 , you generally need to

Check the box next to Run this program as an administrator .

This is the hidden trap.

Alternatively, you can temporarily toggle to Off to test if this resolves the issue.

Right-click the Prototype 2 folder (inside Activision ). Select . At the bottom, under “Attributes,” uncheck Read-only . Click Apply . Check the box that says “Apply changes to this folder, subfolders, and files.” Click OK.