Side by Side Configuration Is Incorrect: Fix in Windows 10

The “Side by side configuration is incorrect” error in Windows 10 usually appears when a program fails to start, often due to a missing or corrupted Microsoft Visual C++ Redistributable package or a damaged .NET Framework installation. You can typically fix it by reinstalling the required Visual C++ Redistributables or using the System File Checker to repair system files.

What Does the Error Mean?

Windows uses a feature called side-by-side (SxS) assemblies to let multiple versions of the same runtime libraries (like Visual C++ or .NET) coexist on one system. Each application declares which exact version it needs in an embedded manifest file. When Windows can’t find or load that declared assembly, it aborts the launch and shows the error. The full message often reads: “The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more details.”

This is not a virus or a sign of hardware failure. It is a software dependency problem, most commonly triggered after a Windows update, a partial uninstall of a runtime, or installing a 32-bit program on a 64-bit system without the matching 32-bit runtime.

Common Causes and Affected Programs

The error appears across a wide range of software, but certain categories are more prone to it:

• Older games and utilities that rely on Visual C++ 2005, 2008, or 2010 runtimes.
• Business and accounting software that bundles its own runtime but fails to install it correctly.
• Photo and video editors that use older codecs or plugins.
• Custom or portable apps that were copied from another machine without their dependencies.

Sometimes the error only occurs after a Windows feature update, because the update resets or removes certain registry entries that map the assembly versions.

Fix 1: Reinstall the Visual C++ Redistributables

This is the most effective fix for the majority of cases. Visual C++ Redistributable packages install the runtime components that many applications need. If one is missing or corrupted, the side-by-side error appears.

1. Open Control Panel > Programs and Features.
2. Look for any entries named Microsoft Visual C++ Redistributable (they have versions like 2005, 2008, 2010, 2012, 2013, 2015-2022).
3. Uninstall all of them, then restart your PC.
4. Download the latest supported Visual C++ Redistributable packages from Microsoft’s official website (both x86 and x64 versions).
5. Install the x64 and x86 versions, then restart again.

If you are unsure which version the failing program needs, install the full set of supported runtimes—it is safe to have multiple versions installed. The 2015-2022 package is a unified installer that covers all those years, but older programs may still need the 2005/2008/2010 packages separately.

Fix 2: Use System File Checker and DISM

If reinstalling runtimes does not help, Windows system files may be damaged. The System File Checker (SFC) scans and repairs protected system files.

1. Right-click the Start button and select Command Prompt (Admin) or Windows PowerShell (Admin).
2. Type sfc /scannow and press Enter. Wait for the scan to finish (it can take 10-20 minutes).
3. If SFC finds issues but cannot fix them, run DISM /Online /Cleanup-Image /RestoreHealth in the same admin window, then run SFC again.
4. Restart your computer and try launching the program again.

This process repairs the Windows component store, which SFC relies on. It is a safe, built-in tool and does not affect your personal files.

Fix 3: Check the Windows Event Log and sxstrace

If the error persists, the system event log contains a more specific reason. Use the built-in Event Viewer to find the exact assembly name that is missing.

1. Press Win + X and select Event Viewer.
2. Go to Windows Logs > Application.
3. Look for a red error entry with source SideBySide that occurred at the time you tried to launch the program.
4. Double-click it and note the text under General. It will mention the exact assembly name and version, e.g., Microsoft.VC90.CRT or Microsoft.Windows.Common-Controls.

You can also run sxstrace.exe from an admin command prompt to generate a detailed trace log:

1. Type sxstrace.exe Trace -logfile:C:\sxslog.etl and press Enter.
2. Try to launch the failing program.
3. Go back to the command prompt and press Ctrl + C to stop tracing.
4. Type sxstrace.exe Parse -logfile:C:\sxslog.etl -outfile:C:\sxslog.txt and press Enter.
5. Open the text file to see the exact error details.

This information helps you identify whether the problem is a missing runtime, a corrupted manifest, or a 32-bit/64-bit mismatch.

Fix 4: Reinstall the Affected Application

Sometimes the application itself is installed incorrectly—its manifest file may be missing or its files are not registered properly. A clean reinstall often resolves this.

1. Uninstall the program via Control Panel > Programs and Features.
2. Restart your PC.
3. Download the latest version of the program from the official website (if available).
4. Right-click the installer and select Run as administrator.
5. Install it, then try launching it.

If the program is a portable app (no installer), try copying it to a different folder or drive. Some portable apps have hard-coded paths that break after a Windows update.

When to Use a Clean Boot or System Restore

If the error started after a recent change, a System Restore can roll back the system to a state before the problem appeared. This is a good option if you have a restore point from before the error began.

1. Type Create a restore point in the Start menu and open it.
2. Click System Restore and follow the wizard to choose a restore point.
3. Confirm and wait for the process to finish (your PC will restart).

A clean boot is a more advanced troubleshooting step that starts Windows with a minimal set of drivers and startup programs. It can help you determine if a background service is interfering with the application’s runtime. To do a clean boot, type msconfig in the Start menu, go to the Services tab, check Hide all Microsoft services, then click Disable all. Restart and test the program. If it works, re-enable services one by one to find the culprit.

Frequently Asked Questions

Why does the error say “side by side”?

Windows uses side-by-side assemblies to allow multiple versions of the same runtime to run simultaneously. The error means the application cannot find the exact version of a runtime library it was built against, usually because that library is missing or corrupted.

Is this error dangerous?

No, it is not a security threat. It is a software dependency issue. However, it can prevent legitimate programs from running, and in rare cases a corrupted system file could indicate a deeper problem, so running SFC is a good precaution.

Will reinstalling Windows fix it?

Yes, a clean install of Windows will definitely fix it because it resets all system files and runtime libraries. But it is a last resort—try the fixes above first, as they solve the problem in the vast majority of cases without losing your files or applications.

Why does the error appear on 64-bit Windows?

Many programs are 32-bit and require the 32-bit (x86) versions of the Visual C++ runtimes. On a 64-bit system, you need both the x64 and x86 versions installed—the x86 ones are not automatically included. The error often occurs when the x86 runtime is missing.

Can I ignore the error and continue using the program?

No, the program will not start at all. The error is a hard failure—Windows blocks the launch because the required assembly is not present. You must fix the dependency to run the program.

Does the error affect all applications?

No, only applications that depend on the specific missing runtime. Other programs that use different runtimes will continue to work normally. That is why the error is often isolated to one or a few programs.

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