Steam Error Code 51 — What It Means & How to Fix It

What Does This Error Mean?

Steam Error Code 51 means the game process failed to start — Steam launched it, but the game itself immediately crashed or refused to run. The message says 'Failed to start game (error code 51)'. This is almost always caused by a compatibility issue, corrupted game files, or a missing system library the game depends on.

Affected Models

Steam (Windows)
Steam (macOS)
Steam (Linux)

Common Causes

The game's executable is incompatible with your version of Windows
Game files are corrupted — one or more essential files are damaged or missing
A required system library like .NET Framework or Visual C++ is missing or outdated
The game is trying to use DirectX features not supported by your graphics driver
An overlay tool (Discord, GeForce Experience, MSI Afterburner) is conflicting with the game launch

How to Fix It

Verify the game's files. In your Steam library, right-click the game > Properties > Local Files > Verify integrity of game files. Let it complete and then try launching.

This is the single most effective first step. Steam checks every file and replaces anything missing or damaged.
Update your graphics drivers. Visit your GPU manufacturer's website (NVIDIA, AMD, or Intel) and install the latest drivers for your graphics card.

Outdated drivers are a common reason games crash immediately on launch. Newer games often require recent driver versions.
Install the required runtimes. Most games need Visual C++ Redistributables and sometimes .NET Framework. Search Microsoft's website for 'Visual C++ Redistributable' and install the latest x64 and x86 versions.

Games install these automatically, but they sometimes fail silently. A manual install ensures they are in place.
Disable all overlay software before launching. Turn off Discord overlay (Discord Settings > Game Overlay), GeForce Experience in-game overlay, and any screen recording tools.

Overlays inject code into the game process. Some games crash immediately when this happens, especially older or poorly optimized titles.
Try setting the game's compatibility mode. In your Steam library, right-click the game > Properties > Compatibility > Force the use of a specific Steam Play compatibility tool (on Linux) — or find the .exe in the install folder, right-click > Properties > Compatibility > Run in compatibility mode for Windows 8.

Older games sometimes need compatibility mode to launch on newer versions of Windows.

When to Call a Professional

Error Code 51 is a local compatibility or file integrity issue. No professional repair is needed — it is software-only. If the game never worked on your PC and you have met the minimum system requirements, contact Steam Support for a refund if it was a recent purchase.

Frequently Asked Questions

Why did Error Code 51 appear after a Windows update?

Windows updates sometimes change how the system handles older executables or update system libraries in ways that break compatibility. Check the game's Steam Community discussions — others playing the same game will likely report the same issue after the same update. Compatibility mode or a game patch from the developer usually fixes these cases.

The game worked yesterday. Nothing changed. Why is it Error Code 51 today?

Even if you changed nothing, Steam may have auto-updated the game overnight and introduced a bug. Check the game's store page for recent update notes and the Steam Community hub for bug reports. If a bad update caused it, the developer usually patches it within a day or two.

Does Error Code 51 mean the game is permanently broken on my PC?

No. Error Code 51 is almost always fixable. The vast majority of cases are resolved by verifying game files, updating drivers, or disabling overlays. Permanent incompatibility is rare and usually only happens with very old games on very new hardware.