When the installer screen launches, click and follow the prompts.

Before diving into fixes, it's helpful to understand why this happens. Black Ops II is a 32-bit application. This means it can only use up to 2GB of your system's RAM (or 4GB with a specific flag enabled), regardless of how powerful your modern gaming PC might be. As you play, the game's memory fills up with textures, shaders, and effects. Once it hits that hard limit and tries to "allocate" more, it fails, causing Windows to force the game to crash with an error.

If the issue persists, your save file might be corrupted. Try creating a new save file and playing through the segment again. System & File Troubleshooting

Corrupted game installation files or modern OS hooks can force memory allocation anomalies. Verify Game Files on Steam

BO2’s .exe is 32-bit and can’t use more than ~3.5GB RAM.

Even on Windows 10/11, BO2 needs older DX9 libs.

If you are encountering this error, this guide will walk you through the most effective fixes, ordered from simplest to most advanced. 1. Verify Game Files (Steam)

Right-click the application executable and select . Head to the Compatibility tab.

If Windows gives you a message saying you cannot disable DEP for a program, it may be a system-level restriction for 32-bit applications, but the attempt is still worth making.

If you play single-player campaign modes or custom Zombies mods and still get crashes, the executable might need access to more system RAM. You can use a community-standard "4GB Patch" tool to alter the game's executable header. This changes it from a 2GB limit to a 4GB Large Address Aware (LAA) structure.

The "Failed to allocate from state pool" error in Call of Duty: Black Ops 2

Also find and set: seta r_gpuSync "0" (if present) seta r_multiGpu "0"

Navigate deeper into the folder within that directory, locate DXSETUP.exe , run it, and accept the license terms to overwrite missing DLL paths. 4. Enable Legacy OS Compatibility Modes