Windows Side-by-Side Configuration Error — Detailed SxS Fix Guide

Detailed guide to fixing Windows Side-by-Side (SxS) configuration errors preventing applications from starting due to missing or mismatched Visual C++ runtime manifests. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Side-by-Side (SxS) assembly allows multiple versions of DLLs to coexist on the same system. The error 'The application has failed to start because its side-by-side configuration is incorrect'. The application manifest specifies which exact version of runtime DLLs it requires. Event Viewer > Application log > SideBySide source shows the specific missing assembly. Most commonly involves MSVCR/MSVCP (Visual C++ Runtime) version mismatches. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Required Visual C++ Redistributable version not installed. Visual C++ Redistributable corrupted after partial uninstallation. Application compiled with a specific VC++ version not available on the system. Multiple VC++ Redistributable versions conflicting in the WinSxS store. Corrupted WinSxS component store preventing assembly resolution. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Check Event Viewer > Application log > SideBySide source for the exact missing assembly name and version. Install all Visual C++ Redistributable versions: 2005, 2008, 2010, 2012, 2013, 2015-2022 (both x86 and x64). Repair existing redistributables: Control Panel > Programs > select VC++ Redist > Change > Repair. Use sxstrace to diagnose: sxstrace Trace -logfile:sxstrace.etl then sxstrace Parse -logfile:sxstrace.etl -outfile:sxstrace.txt. Run sfc /scannow to repair corrupted WinSxS components. Reinstall the failing application to restore its manifest and dependencies. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Windows Error Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.